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Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department of Mathematics Semi-Analytical Iterative Methods for Non-Linear Differential Equations A Thesis Submitted to the College of Education for Pure Science \ Ibn Al-Haitham, University of Baghdad as a Partial Fulfillment of the Requirements for the Degree of Master of Science in Mathematics By Mustafa Mahmood Azeez B.Sc., University of Baghdad, 2010 Supervised By Asst. Prof. Dr. Majeed Ahmed Weli 2017 AD 1438 AH

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Page 1: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

Republic of Iraq

Ministry of Higher Education and Scientific Research

University of Baghdad

College of Education for Pure Science / Ibn Al-Haitham

Department of Mathematics

Semi-Analytical Iterative Methods for Non-Linear

Differential Equations

A Thesis

Submitted to the College of Education for Pure Science \ Ibn Al-Haitham,

University of Baghdad as a Partial Fulfillment of the Requirements for the

Degree of Master of Science in Mathematics

By

Mustafa Mahmood Azeez

B.Sc., University of Baghdad, 2010

Supervised By

Asst. Prof. Dr. Majeed Ahmed Weli

2017 AD 1438 AH

Page 2: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

๏ดพ11๏ดฟูŠุฑูุน ุงู‡ู„ู„ ุงู„ุฐูŠู† ุขู…ู†ูˆุง ู…ู†ูƒู… ูˆุงู„ุฐูŠู† ุฃูˆุชูˆุง ุงู„ุนู„ู… ุฏุฑุฌุงุช

ูŠู… ุญ ุงู„ุฑ ู† ุญู… ุงู„ุฑ ุงู‡ู„ู„ ุณู… ุจ

ู…ุตุฏู‚ ุงู‡ู„ู„ ุงู„ุนุธูŠ

๏ดพ11๏ดฟุงุงู„ูŠุฉ โ€“ ุงู„ู…ุฌุงุฏู„ุฉุณูˆุฑุฉ

Page 3: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

ู‡ุฏุงุก ุงู„ุฅ

ุงู„ุฑุญูŠู…""ุจุณู… ู‡ู„ู„ุง ุงู„ุฑุญู…ู†

ุนู…ู„ูƒ ูˆู‚ู„ ุงุนู…ู„ูˆุง ูุณูŠุฑู‰) (ู… ูˆุฑุณูˆู„ู‡ ูˆุงู„ู…ุคู…ู†ูˆู† ู„ู„ุงู‡

ู…"ุตุฏู‚ ู‡ู„ู„ุง ุงู„ุนุธูŠ"

ุงู„ู„ุญุธุงุช ูˆุงู„ุชุทูŠุจ ..ูˆุงู„ูŠุทูŠุจ ุงู„ู†ู‡ุงุฑ ุฅุงู„ ุจุทุงุนุชูƒ .. ุจูƒุฑุฑ ุฅู„ู‡ูŠ ุงู„ูŠุทูŠุจ ุงู„ู„ูŠู„ ุฅุงู„

..ูˆุงู„ ุชุทูŠุจ ุงู„ุฌู†ุฉ ุฅุงู„ ุจุฑุคูŠุชูƒ ..ูˆุงู„ ุชุทูŠุจ ุงุขู„ุฎุฑุฉ ุฅุงู„ ุจุนููˆ ..ุฅุงู„ ุจุดูƒุฑ

ุฅู„ู‰ ู†ุจูŠ ุงู„ุฑุญู…ุฉ ูˆู†ูˆุฑ ุงู„ุนุงู„ู…ูŠู† ..ู‰ ุงุฃู„ู…ุงู†ุฉ ูˆู†ุตุญ ุงุฃู„ู…ุฉุบ ุงู„ุฑุณุงู„ุฉ ูˆุฃุฏ ุฅู„ู‰ ู…ู† ุจู„

"ู€ู‡ ูˆุณู„ู…ุชุนุงู„ู‰ ุนู„ูŠุตู„ู‰ ู‡ู„ู„ุง " ุฏุณูŠุฏู†ุง ู…ุญู…

ูˆุงู„ู‰ ู…ู† ู…ู‡ุฏ ู„ูŠ ุทุฑูŠู‚ ุงู„ุนู„ู… ..ุฃุณุงุชูƒุชูŠ ุงุฃู„ูุงุถู„ ุงู„ู‰ ุจูŠุงุฑู‚ ุงู„ุนู„ู… ูˆุงู„ู…ุนุฑูุฉ

ุตุฏู‚ุงุก ุงุงู„ู‡ู„ ูˆุงุฃู„ ูˆุงู„ู‰ ,ุฏ ู…ุฌูŠุฏ ุงุญู…ุฏ .ู… .ุฃ ุงู„ูุงุถู„ุฅู„ู‰ ุงุณุชุงุฐูŠ

ู„ูŠ ููŠ ู…ุดูˆุงุฑูŠ ุงู„ุชุนู„ูŠู…ูŠ ู„ู…ุง ุฑุงู† ู„ู‡ู… ู…ู† ุฏุนู…

ู…ุตุทูู‰ ู…ุญู…ูˆุฏ

Page 4: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

Supervisorโ€™s Certification

I certify that this thesis was prepared under my supervision at the department

of mathematics, college of education for pure science / Ibn Al-Haitham,

university of Baghdad as a partial fulfillment of the requirements for the

degree of master of science in mathematics.

Signature:

Name: Asst. Prof. Dr. Majeed Ahmed Weli

Date: 11 / 9 / 2017

In view of the available recommendation, I forward this thesis for debate by

the examining committee.

Signature:

Name: Asst. Prof. Dr. Majeed Ahmed Weli

Head of Department of Mathematics

Date: 11 / 9 / 2017

Page 5: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

Committee Certification

We certify that we have read this thesis entitled "Semi-Analytical Iterative

Methods for Non-Linear Differential Equations" and as examining committee,

we examined the student (Mustafa Mahmood Azeez) in its contains and what is

connected with it, and that in our opinion it is adequate for the partial fulfillment of

the requirement for the degree of Master of Science in Mathematics.

(Member and Supervisor)

Signature:

Name: Asst. Prof. Dr. Majeed A. Weli

Date: 12 / 12 / 2017

(Member)

Signature:

Name: Asst. Prof. Dr. Osama H. Mohammed

Date: 12 /12 / 2017

(Chairman)

Signature:

Name: Prof. Dr. Saad N. Ali

Date: 11 / 12 / 2017

(Member)

Signature:

Name: Lecturer Dr. Ghada H. Ibrahim

Date: 11 / 12 / 2017

Approved by the University Committee of graduate studies.

Signature:

Name: Prof. Dr. Khalid F. Ali

The dean of Education College for Pure Science/ Ibn AL Haitham University of

Baghdad

Date: 12 / 12 / 2017

Page 6: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

ACKNOWLEDGEMENTS

I thank God Almighty our creator for his generosity and great good for helping

me in my scientific career and finishing my current thesis. I would like to thank

my supervisor Dr. Majeed Ahmed Weli who supervised this thesis, and for his

time, patience, motivation and encourage me all the time.

Last but not least. I would like to thank all department staff, my family and dear

friends who have had teach, encourage and support that provided me to finish

my thesis.

Mustafa Mahmood

2017

Page 7: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

Abstract

The main aim of this thesis is to use two semi-analytical iterative

methods to find the analytical solutions for some important problems in

physics and engineering.

The first objective is to use an iterative method which is proposed by

Temimi and Ansari namely (TAM) for finding the analytical solutions for

Riccati, pantograph, and beam deformation equations. Also, the TAM has

been applied for 1D, 2D and 3D nonlinear Burgersโ€™ equations and systems

of equations to get the analytic solutions for each of them. The convergence

of the TAM has been investigated and successfully proved for those

problems.

The second objective is to use an iterative technique based on Banach

contraction method (BCM) which is easy to apply in dealing with nonlinear

terms. The BCM is used to solve the same physical and engineering

problems mentioned above. In addition, we have been presented several

comparisons among the TAM, BCM, variational iteration method (VIM) and

Adomian decomposition method (ADM) with some conclusions and future

works. The presented methods are efficient and have high accuracy. The

TAM and BCM do not require any restrictive assumptions in the nonlinear

case. In addition, both methods do not rely on using any additional

restrictive assumptions as in the ADM or VIM or any other iterative

methods.

The software used for the calculations in this presented thesis is

MATHEMATICAยฎ 10.0.

Page 8: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

AUTHORโ€™S PUBLICATIONS

Journal Papers

1. M. A. Al-Jawary, M. M. Azeez, Efficient Iterative Method for Initial and

Boundary Value Problems Appear in Engineering and Applied Sciences,

International Journal of Science and Research, 6 (6) (2017) 529- 538.

2. M. A. AL-Jawary, M. M. Azeez, G. H. Radhi, Analytical and numerical

solutions for the nonlinear Burgers and advection-diffusion equations by

using a semi-analytical iterative method, Computers & Mathematics with

Applications (under review).

3. M. A. AL-Jawary, M. M. Azeez, G. H. Radhi, Banach Contraction

Method for Some Physical and Engineering Problems, (under

preparation).

Page 9: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

Contents

Subject Page

No.

Introduction i

Chapter 1: Primary Concepts 1

1.1 Introduction 1

1.2 Preliminaries 2

1.2.1 Initial Value Problems 2

1.2.2 Boundary Value Problems 2

1.3 Ordinary Differential Equations (ODEs) 4

1.3.1 Riccati differential equation 5

1.3.2 Analytical methods available in literatures to solve the

Riccati differential equation

5

1.3.3 The Adomian decomposition method 5

1.3.4 Error analysis 8

1.3.5 Variational Iteration Method 11

1.3.6 Pantograph differential equation 15

1.3.7 VIM for solving the pantograph differential equation 16

1.3.8 Beam deformation equation 17

1.3.9 VIM for solving the nonlinear beam deformation problem 18

1.4 Partial Differential Equations (PDEs) 22

1.4.1 Burgersโ€™ equation 22

1.4.2 Exact and numerical solutions for nonlinear Burgersโ€™

equation by ADM

24

1.4.3 The VIM to solve the 2D Burgersโ€™ equation 30

Chapter 2: Semi-Analytical Iterative Method for Solving Some

Ordinary and Partial Differential Equations

33

2.1 Introduction 33

2.2 The basic idea of the TAM 34

2.3 The convergence of the TAM 35

2.4 Application of the TAM with convergence for the ODE and

PDE

36

2.4.1 Exact and numerical solutions for nonlinear Riccati

equation by TAM

36

2.4.2 TAM for solving linear pantograph equation 42

2.4.3 Solving the nonlinear beam equation by using the TAM 45

2.4.4 Solving the nonlinear Burgersโ€™ equation by using TAM 50

2.4.5 Solving the nonlinear system of Burgersโ€™ equations by

the TAM

64

Page 10: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

Chapter 3: Banach Contraction Method for Solving Some

Ordinary and Partial Differential Equations

87

3.1 Introduction 87

3.2 Contractions: Definition and Example 88

3.3 Banach Contraction Principle 89

3.3.1 Solution of differential equations using Banach

contraction principle

89

3.4 The basic idea of the BCM 91

3.5 The BCM to solve Riccati, pantograph and beam deformation

equations

92

3.5.1 Exact and numerical solutions for nonlinear Riccati

equation by BCM

92

3.5.2 BCM for solving linear pantograph equation 96

3.5.3 Solving the nonlinear beam equation by using BCM 97

3.5.4 Solving the nonlinear Burgersโ€™ equation by using the

BCM

101

3.5.5 Solving the nonlinear system of Burgersโ€™ equations by

using BCM

108

Chapter 4: Conclusions and Future Works 117

4.1 Introduction 117

4.2 Conclusions 117

4.3 Future Works 121

References 122

Appendices 130

Appendix A: Code of Mathematica for chapter one (ADM) 130

Appendix B: Code of Mathematica for chapter one (VIM) 134

Appendix C: Code of Mathematica for chapter two (TAM) 136

Appendix D: Code of Mathematica for chapter three (BCM) 137

Page 11: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

List of Tables

Tableโ€™s name Pageโ€™s

No. Table 1.1: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the ADM,

where ๐‘› = 1, โ€ฆ ,6. 11

Table 1.2: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the VIM,

where ๐‘› = 1, โ€ฆ ,6. 14

Table 1.3: Results of the absolute errors for VIM. 21

Table 1.4: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the ADM. 30

Table 1.5: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the VIM. 32

Table 2.1: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the TAM. 41

Table 2.2: Results of the absolute errors for TAM. 48

Table 2.3: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the TAM,

where ๐‘› = 1, โ€ฆ ,4.

56

Table 3.1: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the BCM,

where ๐‘› = 1, โ€ฆ ,6.

95

Table 3.2: Results of the absolute errors for BCM. 100

Table 3.3: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the BCM. 104

Table 4.1: Comparative results of the maximal error remainder:

๐‘€๐ธ๐‘…๐‘›for TAM, BCM, VIM and ADM, where ๐‘› = 1, โ€ฆ ,6. 118

Table 4.2: Comparative results for the absolute errors of the TAM,

BCM, VIM and HPM.

119

Table 4.3: Comparative results the maximal error remainder:

๐‘€๐ธ๐‘…๐‘› for TAM, BCM, VIM and ADM, where ๐‘› = 1, โ€ฆ ,4. 120

Page 12: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

List of Figures

Figureโ€™s name Pageโ€™s

No.

Figure 1.1: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 6 by

ADM.

11

Figure 1.2: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 6 by

VIM.

14

Figure 1.3: Beam on the elastic bearing. 18

Figure 1.4: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 4 by

ADM.

30

Figure 1.5: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 4 by

V1M.

32

Figure 2.1: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 6 by

TAM.

41

Figure 2.2: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 4 by

TAM.

56

Figure 3.1: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 6 by

BCM.

95

Figure 3.2: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 4 by

BCM.

104

Figure 4.1: Comparison of the maximal error remainder for TAM,

BCM, VIM and ADM.

118

Figure 4.2: Comparison of the maximal error remainder for TAM,

BCM, VIM and ADM.

120

Page 13: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

LIST OF SYMBOLS AND ABBREVIATIONS

๐ด๐‘›: Adomian Polynomials

๐ด๐ท๐‘€: Adomian Decomposition Method

๐ต๐ถ๐‘€: Banach Contraction Method

๐ต๐‘‰๐‘ƒ: Boundary Value Problem

๐ธ๐‘…: Error Remainder

๐ป๐ด๐‘€: Homotopy Analysis Method

๐ผ๐‘‰๐‘ƒ: Initial Value Problem

Re: Reynolds number

๐‘€๐ธ๐‘…: Maximum Error Remainder

๐‘‚๐ท๐ธ๐‘ : Ordinary Differential Equations

๐‘ƒ๐ท๐ธ๐‘ : Partial Differential Equations

๐‘‡๐ด๐‘€: Temimi- Ansari Method

๐‘‰๐ผ๐‘€: Variational Iteration Method

๐‘‰๐ผ๐ธ: Volterra Integral Equation

๐œ†: Lagrangeโ€™s multiplayer

๐›ฟ: Variation

|๐‘Ÿ๐‘›|: Absolute Error

โ€– โ€–: Norm

Page 14: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

Introduction

i

INTRODUCTION

The ordinary and partial differential equations play an important role in

many problems that appears in different fields of engineering and applied

sciences. The past few decades have seen a significant progress to implement

analytical, approximate methods for solving linear and nonlinear differential

equations. For examples: Adomian decomposition method (ADM) [68],

variational iteration method (VIM) [4], homotopy perturbation method

(HPM) [63], differential transform method (DTM) [78] and many others.

Although these methods provided or given some useful solutions, however,

some drawbacks have emerged such as the calculation of the Adomian

polynomials for the nonlinear problems in ADM, calculate the Lagrange

multiplier in the VIM and the calculation became more complicated after

several iterations, homotopy construction and solving the corresponding

equations in HPM.

In this thesis, some of the ordinary and partial differential equations that

appear in the problems of chemistry, physics, engineering and other applied

sciences will be solved by using iterative methods.

One of these equations is the Riccati equation, which is an initial value

problem of nonlinear ordinary differential equation, which plays a significant

role in many fields of applied science such as random processes, optimal

control, diffusion problems, network synthesis and financial mathematics

[26].

The other one is the pantograph equation which is originated from the

work of Ockendon and Tayler on the collection of current by the pantograph

head of an electric locomotive [38]. The pantograph equations are appeared in

Page 15: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

Introduction

ii

modeling of various problems in engineering and sciences such as biology,

economy, control and electrodynamics [16].

Moreover, the beam deformation equation will be solved, which is a

nonlinear boundary value problem (BVP) which is frequently used as

mathematical models in viscoelastic, inelastic flows and deformation of

beams [1].

Furthermore, the other equation that will be solved is the Burgersโ€™

equation which is a partial differential equation and firstly introduced by

Harry Bateman in 1915 [27] and it was subsequently processed to become as

Burgersโ€™ equation [45]. Burgersโ€™ equation has a lot of importance in

engineering and physical fields, especially in problems that have the form of

nonlinear equations and equation systems. The applications of Burgersโ€™

equations by mathematical scientists and researchers has become more

commonplace and interesting, it has been known that this equation describes

different types of phenomena such as modeling of dynamics, heat conduction,

acoustic waves, turbulence and many others [5, 10, 36, 45, 56 , 61, 77]. In

recent decades, some scientists and researchers used some methods and

techniques to solve these types of problems [22, 39, 42, 44, 71] which will be

discussed in this thesis and solved in reliable iterative methods.

Recently, Temimi and Ansari have introduced a semiโ€“analytical iterative

method namely (TAM) for solving nonlinear problems [28]. The main feature

of the TAM is very effective and reliable, does not require any restrictive

assumptions to deal with nonlinear terms, time saver, and has a higher

convergence and accuracy. The TAM was inspired from the homotopy

analysis method (HAM) [70] and it is one of the famous iterative methods

that used for solving nonlinear problems [65]. Moreover, the TAM is

successfully used to solve many differential equations, such as Duffing

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Introduction

iii

equations [51], kortewegโ€“de vries equations [18], chemistry problems [52]

and nonlinear thin film flow problems [53].

In addition, Sehgal and Bharucha-Reid proved the probabilistic version

of the classical Banach contraction method (BCM) in 1972 [3]. The BCM

characterized as one of the developments of Picardโ€™s method where the ease

of application clearly observed which makes it distinct from the other known

iterative methods. The BCM used to solve various nonlinear functional delay

equations including partial differential equations (PDE), ordinary differential

equations (ODE), system of ODEs and PDEs and algebraic equations [75].

The main advantages of the BCM, it does not require any external

assumptions to deal with the nonlinear terms like the TAM. It avoided the

large computational work or calculated the Lagrange's multipliers in the VIM.

This thesis has been arranged as follows: in chapter one, the introductory

concepts about the non-linear differential equations (ordinary and partial) and

some analytic and approximate methods will be introduced to solve some

scientific applications, such as ADM and VIM. Chapter two presents the basic

idea of the TAM as well as an overview of the convergence of TAM, which is

based on the Banach fixed-point theory. Furthermore, the TAM is

successfully implemented to solve the Riccati equations, pantograph, and

beam deformation equations. In addition, the TAM will be implemented to

solve the Burgers and system equations in 1D, 2D and 3D to illustrate the

efficiency and accuracy of the proposed method. In chapter three, the basic

concepts of the BCM will be presented, and the application of the BCM for

the same problems solved by TAM will be introduced. Finally, in Chapter

four the conclusions and future works will be given.

Page 17: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

CHAPTER 1

PRIMARY

CONCEPTS

Page 18: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

Chapter One Primary Concepts

1

Chapter 1

Primary Concepts

1.1 Introduction

The importance of the non-linear differential equations highlights when

dealing with the problems that are occurring in different fields such as

physical and chemical sciences and engineering. Many of these problems are

of a nonlinear form. It is known that there is a difficulty in to solving these

nonlinear problems and require to use efficient methods to get the analytic,

approximate or numerical solutions.

Moreover, the problems that will be solved in this thesis are

mathematical models contain non-linear ODEs such as Riccati equation,

pantograph equation, beam deformation equation and nonlinear PDEs such as

Burgersโ€™ equation, that appeared in many engineering and applied sciences.

This chapter contains four sections. In section two, some definitions and

theorems that will be used in the next chapters will be given. In section three,

some types of ODEs are presented, such as Riccati, pantograph and beam

deformation equations. In addition, some analytic and approximate methods

will be introduced to solve some scientific applications, such as ADM and the

VIM. Finally, in section four, the Burgersโ€™ equations and system of equations

in 1D, 2D, and 3D will be introduced. Also, the 1D, 2D Burgersโ€™ equations

will be given in literature by ADM and VIM.

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Chapter One Primary Concepts

2

1.2 Preliminaries

1.2.1 Initial Value Problems [6]:

Differential equations are often divided into two classes, ordinary and

partial, according to the number of independent variables. A more meaningful

division, however, is between initial value problems, which usually model

time-dependent phenomena, and boundary value problems, which generally

model steady-state systems.

A differential equation (DE) that has given conditions allows us to find

the specific function that satisfies a given DE rather than a family of

functions. These types of problems are called initial value problems (IVP). In

physics or other sciences, frequently amounts to solving an initial value

problem. For example, an initial value problem is a differential equation

๐‘ฃโ€ฒ(๐‘ฅ) = ๐‘“(๐‘ฅ, ๐‘ฃ(๐‘ฅ)), with ๐‘“: ๐œƒ โŠ‚ ๐‘… ร— ๐‘…๐‘› โ†’ ๐‘…๐‘›,

where ๐œƒ is an open set of ๐‘… ร— ๐‘…๐‘›, together with a point in the domain of ๐‘“,

(๐‘ฅ0, ๐‘ฃ0) โˆˆ ๐œƒ called the initial condition. A solution to an initial value problem

is a function ๐‘ฃ that is a solution to the differential equation and satisfies

๐‘ฃ(๐‘ฅ0) = ๐‘ฃ0.

1.2.2 Boundary Value Problems [6]:

When imposed an ordinary or a partial differential equation the

conditions are given at more than one point and the differential equation is of

order two or greater, it is called a boundary value problem (BVP). For

example, if the independent variable is time over the domain [0,1], a

boundary value problem would specify values for ๐‘ฃ(๐‘ฅ) at both ๐‘ฅ =

0 and ๐‘ฅ = 1, whereas an initial value problem would specify a value of

๐‘ฃ(๐‘ฅ) and ๐‘ฃโ€ฒ(๐‘ฅ) at time ๐‘ฅ = 0. In addition, there are four types of boundary

value problems or boundary conditions: Dirichlet, Neunmann, Mixed, Robin

boundary conditions.

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Chapter One Primary Concepts

3

The boundary value problems have a greater importance in various

scientific fields. Many of researchers and scientists experiencing in their

scientific researchers have a problem in finding the desired solution for those

boundary value problems. These problems come with boundary conditions,

which are satisfying the solution. In some cases, these problems are

formulated from BVP to Volterra integral equation. The integral equation

make the reaching to the solution simple and easy.

Definition 1.1: [6]

An integral equation is called Volterra integral equation (VIE) if limits

of integration are functions of x rather than constants. The first kind Volterra

integral equations, is:

๐‘“(๐‘ฅ) = ฮป โˆซ ๐‘˜(๐‘ฅ, ๐‘ก)๐‘ฃ(๐‘ก)๐‘‘๐‘ก

๐‘ฅ

๐‘Ž

, (1.1)

where the unknown function ๐‘ฃ(๐‘ฅ) appears only inside integral sign, and the

Volterra integral equations of the second kind is

๐‘ฃ(๐‘ฅ) = ๐‘“(๐‘ฅ) + ฮป โˆซ ๐‘˜(๐‘ฅ, ๐‘ก)๐‘ฃ(๐‘ก)๐‘‘๐‘ก,

๐‘ฅ

๐‘Ž

(1.2)

where the unknown function ๐‘ฃ(๐‘ฅ) appears inside and outside the integral sign.

Definition 1.2: [57]

Let (๐‘‹, ๐‘‘) be a metric space. Then a mapping ๐น: ๐‘‹ โ†’ ๐‘‹, is said to be

Lipschitz if there exists a real number ๐‘˜ โ‰ฅ 0, such that

๐‘‘(๐น(๐‘ฅ), ๐น(๐‘ฆ)) โ‰ค ๐‘˜๐‘‘(๐‘ฅ, ๐‘ฆ) for all ๐‘ฅ, ๐‘ฆ in ๐‘‹.

In addition ๐น is called a contraction mapping on ๐‘‹ if ๐‘˜ < 1.

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Chapter One Primary Concepts

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Theorem 1.1 (Banach Fixed Point Theorem): [69]

Let (๐‘‹, ๐‘‘) be a non-empty complete metric space with a contraction

mapping ๐น: ๐‘‹ โ†’ ๐‘‹. Then ๐น admits a unique fixed-point x* โˆˆ ๐‘‹

F(x*) = x*

Theorem 1.2: [57]

Let ๐น be a mapping of a complete metric space (๐‘‹, ๐‘‘) into itself such

that ๐น๐‘˜ is a contraction mapping of ๐‘‹ for some positive integer ๐‘˜. Then ๐น has

a unique fixed point in ๐‘‹.

Proof: See [57].

1.3 Ordinary Differential Equations (ODEs)

An ordinary differential equation is a relation containing one real

independent variable ๐‘ฅ โˆˆ ๐‘… = (โˆ’โˆž, โˆž), the real dependent variable v, and

some of its derivatives ( ๐‘ฃโ€ฒ, ๐‘ฃโ€ฒโ€ฒ, ๐‘ฃโ€ฒโ€ฒโ€ฒ, โ€ฆ , ๐‘ฃ๐‘›), ๐‘ฃโ€ฒ =๐‘‘๐‘ฃ

๐‘‘๐‘ฅ. ODEs arise in many

contexts of mathematics and science. Various differentials, derivatives, and

functions become related to each other via equations, and thus an ODE is a

result that describes dynamically changing phenomena, evolution, or

variation. Also, in specific mathematical fields, include geometry and

analytical mechanics, and scientific fields include much of physics, chemistry

and biology [4].

In this section, we have examined three specific problems in physical

and engineering sciences that are governed by non-linear ODEs and they are

solved by using ADM and VIM.

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Chapter One Primary Concepts

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1.3.1 Riccati differential equation

The Riccati differential equation is named after the Italian noble man

Count Jacopo Francesco Riccati (1676-1754) [26]. This equation has many

applications such as network synthesis, financial mathematics [12], control

the boundary arising in fluid structure interaction [31]. Consider the following

nonlinear Riccati differential equation [20].

๐‘ฃโ€ฒ(๐‘ฅ) = ๐‘(๐‘ฅ) + ๐‘ž(๐‘ฅ)๐‘ฃ(๐‘ฅ) + ๐‘Ÿ(๐‘ฅ)๐‘ฃ2(๐‘ฅ), ๐‘ฃ(๐‘ฅ0) = ๐›ผ, ๐‘ฅ0 โ‰ค ๐‘ฅ โ‰ค ๐‘‹๐‘“ , (1.3)

where ๐‘(๐‘ฅ), ๐‘ž(๐‘ฅ) and ๐‘Ÿ(๐‘ฅ) are continuous functions, ๐‘ฅ0, ๐‘‹๐‘“ and ฮฑ are

arbitrary constants, and ๐‘ฃ(๐‘ฅ) is unknown function.

A substantial amount of research work has been done to develop the

solution for Riccati differential equation. The most used methods are ADM

[68], HAM [34]. Taylor matrix method [59] and Haar wavelet method [79],

HPM [82] combination of Laplace Adomian decomposition and Pade

approximation methods [64], and many other methods available in the

literature.

1.3.2 Analytical methods available in literatures to solve the

Riccati differential equation

In this subsection, the ADM and VIM will be used to solve the nonlinear

Riccati differential equation.

1.3.3 The Adomian decomposition method

In the early 1980s, George Adomian had introduced the ADM [22, 23,

24]. This method plays an important role in applied mathematics. The

importance of the ADM is due to its strength and effectiveness, and it can

easily deal with many types of ODEs, PDEs (linear and nonlinear), integral

equations and the other types of equations [7]. It consists of decomposing the

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Chapter One Primary Concepts

6

unknown function ๐‘ฃ(๐‘ฅ) of any equation into a sum of an infinite number of

components defined by the decomposition series.

๐‘ฃ(๐‘ฅ) = โˆ‘ ๐‘ฃ๐‘›(๐‘ฅ)

โˆž

๐‘›=0

or equivalently

๐‘ฃ(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) + ๐‘ฃ1(๐‘ฅ) + ๐‘ฃ2(๐‘ฅ) + โ‹ฏ.

Where the linear components ๐‘ฃ๐‘›(๐‘ฅ), ๐‘› โ‰ฅ 0, are evaluated in recursive

manner. The decompositions method concerns itself with finding the

components ๐‘ฃ0, ๐‘ฃ1, ๐‘ฃ2, ... etc.

The zero component is identified by all terms that are not included under

the integral sign. Consequently, those components ๐‘ฃ๐‘–(๐‘ฅ), ๐‘– > 1 of the

unknown function ๐‘ฃ(๐‘ฅ) are completely determined by setting the recurrence.

Consider the following nonlinear differential equation

๐ฟ๐‘ฃ + ๐‘๐‘ฃ = ๐‘“(๐‘ฅ), (1.4)

where ๐ฟ and ๐‘ are linear and nonlinear operators, respectively, and ๐‘“(๐‘ฅ) is

the source inhomogeneous term. The ADM introduces for Eq. (1.4) in the

form

๐‘ฃ0(๐‘ฅ) = ๐‘“(๐‘ฅ),

๐‘ฃ๐‘›+1(๐‘ฅ) = โˆซ (โˆ‘ ๐‘ฃ๐‘›(๐‘ก))๐‘‘๐‘ก, ๐‘› โ‰ฅ 0

โˆž

๐‘›=0

๐‘ฅ

0

(1.5)

For the nonlinear solution ๐‘ฃ(๐‘ฅ), and the infinite series of polynomials

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Chapter One Primary Concepts

7

๐‘ฃ(๐‘ฅ) = โˆ‘ ๐ด๐‘›(๐‘ฃ0, ๐‘ฃ1, โ€ฆ , ๐‘ฃ๐‘›)

โˆž

๐‘›=0

,

where the components ๐‘ฃ๐‘›(๐‘ฅ) of the solution ๐‘ฃ(๐‘ฅ) will be determined,

recurrently and ๐ด๐‘› are the Adomian polynomials which are obtained from the

definitional formula [24]

๐ด๐‘› =1

๐‘›!

๐‘‘๐‘›

๐‘‘๐œ†๐‘›[๐‘“(โˆ‘ ๐œ†๐‘–๐‘ฃ๐‘–)

๐‘›

๐‘–=0

]๐œ†=0, ๐‘› = 1,2, โ€ฆ

The formulas of the first several Adomian polynomials from ๐ด0 to ๐ด5, will be

listed below as given in [24]

๐ด0 = ๐‘“(๐‘ฃ0),

๐ด1 = ๐‘ฃ1๐‘“โ€ฒ(๐‘ฃ0),

๐ด2 = ๐‘ฃ2๐‘“โ€ฒ(๐‘ฃ0) +1

2!๐‘ฃ1

2๐‘“โ€ฒโ€ฒ(๐‘ฃ0),

๐ด3 = ๐‘ฃ3๐‘“โ€ฒ(๐‘ฃ0) + ๐‘ฃ1๐‘ฃ2๐‘“โ€ฒโ€ฒ(๐‘ฃ0) +1

3!๐‘ฃ1

3๐‘“โ€ฒโ€ฒโ€ฒ(๐‘ฃ0),

๐ด4 = ๐‘ฃ4๐‘“โ€ฒ(๐‘ฃ0) + (1

2!๐‘ฃ2

2 + ๐‘ฃ1๐‘ฃ3)๐‘“โ€ฒโ€ฒ(๐‘ฃ0) +1

2!๐‘ฃ1

2๐‘ฃ2๐‘“โ€ฒโ€ฒโ€ฒ(๐‘ฃ0)

+1

4!๐‘ฃ1

4๐‘“โ€ฒโ€ฒโ€ฒโ€ฒ(๐‘ฃ0),

๐ด5 = ๐‘ฃ5๐‘“โ€ฒ(๐‘ฃ0) + (๐‘ฃ2๐‘ฃ3 + ๐‘ฃ1๐‘ฃ4)๐‘“โ€ฒโ€ฒ(๐‘ฃ0) + (1

2!๐‘ฃ1๐‘ฃ2

2 +1

2!๐‘ฃ1

2๐‘ฃ3)๐‘“โ€ฒโ€ฒโ€ฒ(๐‘ฃ0)

+1

3!๐‘ฃ1

3๐‘ฃ2๐‘“โ€ฒโ€ฒโ€ฒโ€ฒ(๐‘ฃ0) +1

5!๐‘ฃ1

5๐‘“โ€ฒโ€ฒโ€ฒโ€ฒโ€ฒ(๐‘ฃ0),

โฆ™

and so on.

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Chapter One Primary Concepts

8

Note 1.1:

It is worth mentioning that we can use the transformation formula of

converting multiple integrals to single [6]

โˆซ โˆซ โ€ฆ โˆซ ๐‘ฃ(๐‘ฅ๐‘›)๐‘‘๐‘ฅ๐‘› โ€ฆ ๐‘‘๐‘ฅ1

๐‘ฅ

0

=1

(๐‘› โˆ’ 1)!โˆซ (๐‘ฅ โˆ’ ๐‘ก)๐‘›โˆ’1๐‘ฃ(๐‘ก)๐‘‘๐‘ก. (1.6)

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

1.3.4 Error analysis

We used the appropriate function of the maximal error remainder [35,

54] to assess the accuracy of the approximate solution.

๐ธ๐‘…๐‘›(๐‘ฅ) = ๐ฟ(๐‘ฃ) โˆ’ ๐‘(๐‘ฃ) โˆ’ ๐‘“. (1.7)

The maximal error remainder is

๐‘€๐ธ๐‘…๐‘› = max0โ‰ค๐‘ฅโ‰ค1

|๐ธ๐‘…๐‘›(๐‘ฅ)|. (1.8)

The ADM will be implemented to solve the Riccati differential equation

Example 1.1 [74]:

Let us consider the Riccati equation of the form.

๐‘ฃโ€ฒ = โˆ’๐‘ฃ2 + 1, with initial condition ๐‘ฃ(0) = 0. (1.9)

Eq. (1.9) can be converted to the following Volterra integral equation

๐‘ฃ(๐‘ฅ) = ๐‘ฅ โˆ’ โˆซ ๐‘ฃ2(๐‘ก)๐‘‘๐‘ก, (1.10)๐‘ฅ

0

The Adomain method proposes that the solution ๐‘ฃ(๐‘ฅ) can be expressed by the

decomposition series:

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Chapter One Primary Concepts

9

๐‘ฃ(๐‘ฅ) = โˆ‘ ๐‘ฃ๐‘›(๐‘ฅ)

โˆž

๐‘›=0

,

and the nonlinear term ๐‘ฃ2, be equated to:

๐‘ฃ2 = โˆ‘ ๐ด๐‘›.

โˆž

๐‘›=0

Therefore, Eq. (1.10) will be:

โˆ‘ ๐‘ฃ๐‘›(๐‘ฅ) = ๐‘ฅ โˆ’ โˆซ (โˆ‘ ๐ด๐‘›

โˆž

๐‘›=0

(๐‘ก))๐‘‘๐‘ก, (1.11)๐‘ฅ

0

โˆž

๐‘›=0

The following recursive relation:

๐‘ฃ0 = ๐‘ฅ,

๐‘ฃ๐‘›+1 = โˆ’ โˆซ (โˆ‘ ๐ด๐‘›

โˆž

๐‘›=0

(๐‘ก)) ๐‘‘๐‘ก, ๐‘ฅ

0

๐‘› โ‰ฅ 0. (1.12)

Now, we find Adomian polynomial ๐ด๐‘›.

๐ด0 = ๐‘“(๐‘ฃ0) = ๐‘ฃ02,

๐ด1 = ๐‘ฃ1 ๐‘“โ€ฒ(๐‘ฃ0) = 2๐‘ฃ0๐‘ฃ1,

๐ด2 = ๐‘ฃ2๐‘“โ€ฒ(๐‘ฃ0) +1

2!๐‘ฃ1

2๐‘“โ€ฒโ€ฒ(๐‘ฃ0) = 2๐‘ฃ0๐‘ฃ2 + ๐‘ฃ12,

๐ด3 = ๐‘ฃ3๐‘“โ€ฒ(๐‘ฃ0) + ๐‘ฃ1๐‘ฃ2๐‘“โ€ฒโ€ฒ(๐‘ฃ0) +1

3!๐‘ฃ1

3๐‘“โ€ฒโ€ฒโ€ฒ(๐‘ฃ0) = 2๐‘ฃ0๐‘ฃ3 + 2๐‘ฃ1๐‘ฃ2,

โ‹ฎ

Consequently, by applying the Mathematicaโ€™s code, see appendix A, we get

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Chapter One Primary Concepts

10

๐‘ฃ0 = ๐‘ฅ,

๐‘ฃ1 = โˆ’ โˆซ ๐ด0(๐‘ก)๐‘‘๐‘ก = โˆ’๐‘ฅ3

3,

๐‘ฅ

0

๐‘ฃ2 = โˆ’ โˆซ ๐ด1(๐‘ก)๐‘‘๐‘ก =2๐‘ฅ5

15,

๐‘ฅ

0

๐‘ฃ3 = โˆ’ โˆซ ๐ด2(๐‘ก)๐‘‘๐‘ก = โˆ’17๐‘ฅ7

315,

๐‘ฅ

0

๐‘ฃ4 = โˆ’ โˆซ ๐ด3(๐‘ก)๐‘‘๐‘ก =62๐‘ฅ9

2835,

๐‘ฅ

0

๐‘ฃ5 = โˆ’ โˆซ ๐ด4(๐‘ก)๐‘‘๐‘ก = โˆ’1382๐‘ฅ11

155925,

๐‘ฅ

0

๐‘ฃ6 = โˆ’ โˆซ ๐ด5(๐‘ก)๐‘‘๐‘ก =21844๐‘ฅ13

6081075,

๐‘ฅ

0

Then, we have

๐‘ฃ(๐‘ฅ) = ๐‘ฅ โˆ’๐‘ฅ3

3+

2๐‘ฅ5

15โˆ’

17๐‘ฅ7

315+

62๐‘ฅ9

2835โˆ’

1382๐‘ฅ11

155925+

21844๐‘ฅ13

6081075.

The obtained series solution in Eq. (1.9) can be used to calculate the

maximal error remainder for show the highest accuracy level that we can

achieve. It can be clearly seen in table 1.1 and figure 1.1 that by increasing the

iterations the errors will be reduced.

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Chapter One Primary Concepts

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Table 1.1: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the ADM, where ๐‘› =1, โ€ฆ ,6.

n ๐‘ด๐‘ฌ๐‘น๐’ by ADM

1 6.65556 ร— 10โˆ’5

2 3.76891 ร— 10โˆ’7

3 1.96289 ร— 10โˆ’9

4 9.72067 ร— 10โˆ’12

5 4.65513 ร— 10โˆ’14

6 2.15106 ร— 10โˆ’16

Figure 1.1: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 6 by ADM.

1.3.5 Variational Iteration Method

The method used to solve the Riccati differential equation is called the

VIM [20]. The VIM established by Ji-Huan He in 1999 is now used to deal

with a wide variety of linear and nonlinear, homogeneous and inhomogeneous

equations [40, 41]. The obtained series can be employed for numerical

purposes if exact solution is not obtainable. To illustrate the basic concepts of

the VIM, we consider the following nonlinear equation [39, 43]:

๐ฟ๐‘ฃ(๐‘ฅ) + ๐‘๐‘ฃ(๐‘ฅ) = ๐‘“(๐‘ฅ), ๐‘ฅ > 0, (1.13)

1 2 3 4 5 6

10 15

10 13

10 11

10 9

10 7

10 5

n

ME

Rn

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Chapter One Primary Concepts

12

where, ๐ฟ is a linear operator, ๐‘ a nonlinear operator and ๐‘“(๐‘ฅ) is the source of

the inhomogeneous term. The VIM introduces functional for Eq. (1.13) in the

form:

๐‘ฃ๐‘›+1(๐‘ฅ) = ๐‘ฃ๐‘›(๐‘ฅ) + โˆซ ๐œ†(๐‘ )(๐ฟ๐‘ฃ๐‘›(๐‘ ) + ๐‘๏ฟฝ๏ฟฝ๐‘›(๐‘ ) โˆ’ ๐‘“(๐‘ ))๐‘‘๐‘ , (1.14)๐‘ฅ

0

where ๐œ† is a general Lagrangian multiplier which can be identified optimally

via the variational theory, and ๏ฟฝ๏ฟฝ๐‘› as a restricted variation. The Lagrange

multiplier ๐œ† may be constant or a function and it is given by the general

formula [8, 9]:

๐œ†(๐‘ ) = (โˆ’1)๐‘›1

(๐‘› โˆ’ 1)!(๐‘  โˆ’ ๐‘ฅ)๐‘›โˆ’1. (1.15)

However, for fast convergence, the function ๐‘ฃ0(๐‘ฅ) should be selected by

using the initial condition for ODE as follows:

๐‘ฃ0(๐‘ฅ) = ๐‘ฃ(0), for first order.

๐‘ฃ0(๐‘ฅ) = ๐‘ฃ(0) + ๐‘ฅ๐‘ฃโ€ฒ(0), for second order.

๐‘ฃ0(๐‘ฅ) = ๐‘ฃ(0) + ๐‘ฅ๐‘ฃโ€ฒ(0) +1

2!๐‘ฅ2๐‘ฃ"(0), for third order.

โฆ™

and so on.

The successive approximations ๐‘ฃ๐‘›+1, ๐‘› โ‰ฅ 0 of the solution ๐‘ฃ๐‘›(๐‘ฅ) will

be readily upon using selective function ๐‘ฃ0(๐‘ฅ). Consequently, the solution is

given by

๐‘ฃ(๐‘ฅ) = ๐‘™๐‘–๐‘š๐‘›โ†’โˆž

๐‘ฃ๐‘›(๐‘ฅ).

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Chapter One Primary Concepts

13

In what follows, the VIM will be implemented to solve the Riccati

differential equation.

Example 1.2 [74]:

Rewrite the example 1.1 and solve it by VIM.

๐‘ฃโ€ฒ = โˆ’๐‘ฃ2 + 1, with initial condition ๐‘ฃ(0) = 0. (1.16)

By using Eq. (1.14), we get

๐‘ฃ๐‘›+1(๐‘ฅ) = ๐‘ฃ๐‘›(๐‘ฅ) + โˆซ [๐œ†(๐‘ )(๐‘ฃ๐‘›โ€ฒ + ๐‘ฃ๐‘›

2(๐‘ ) โˆ’ 1)]๐‘ฅ

0

๐‘‘๐‘ , (1.17)

By using the formula in Eq. (1.15) leads to ฮป = โˆ’1. Substituting this value of

the Lagrange multiplier ฮป = โˆ’1 into the functional Eq. (1.17) gives the

iteration formula:

๐‘ฃ๐‘›+1(๐‘ฅ) = ๐‘ฃ๐‘›(๐‘ฅ) โˆ’ โˆซ (๐‘ฃ๐‘›โ€ฒ + ๐‘ฃ๐‘›

2(๐‘ ) โˆ’ 1)๐‘ฅ

0

๐‘‘๐‘ . (1.18)

The initial approximation will be:

๐‘ฃ0(๐‘ฅ) = ๐‘ฃ(0) = 0,

By using equation (1.18), the following successive approximations will be

obtained:

๐‘ฃ0 = 0,

๐‘ฃ1 = ๐‘ฃ0 โˆ’ โˆซ (๐‘ฃ0โ€ฒ + ๐‘ฃ0

2(๐‘ ) โˆ’ 1)๐‘ฅ

0

๐‘‘๐‘  = ๐‘ฅ,

๐‘ฃ2 = ๐‘ฃ1 โˆ’ โˆซ (๐‘ฃ1โ€ฒ + ๐‘ฃ1

2(๐‘ ) โˆ’ 1)๐‘ฅ

0

๐‘‘๐‘  = ๐‘ฅ โˆ’๐‘ฅ3

3,

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Chapter One Primary Concepts

14

๐‘ฃ3 = ๐‘ฃ2 โˆ’ โˆซ (๐‘ฃ2โ€ฒ + ๐‘ฃ2

2(๐‘ ) โˆ’ 1)๐‘ฅ

0

๐‘‘๐‘  = ๐‘ฅ โˆ’๐‘ฅ3

3+

2๐‘ฅ5

15โˆ’

๐‘ฅ7

63,

By continuing in this way till n = 6, we have

๐‘ฃ6(๐‘ฅ) = ๐‘ฅ โˆ’๐‘ฅ3

3+

2๐‘ฅ5

15โˆ’

17๐‘ฅ7

315+

62๐‘ฅ9

2835โˆ’

1382๐‘ฅ11

155925+

20404๐‘ฅ13

6081075

โˆ’766609๐‘ฅ15

638512875+

4440998๐‘ฅ17

10854718875โˆ’

3206482๐‘ฅ19

24105934125+ โ‹ฏ , (1.19)

Table 1.2 and Figure 1.2 illustrate the convergence of the solution

through the use of the maximal error remainder which can be clearly seen, the

error will be reduced by increasing the number of iterations.

Table 1.2: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the VIM, where ๐‘› =1, โ€ฆ ,6.

n ๐‘ด๐‘ฌ๐‘น๐’ by VIM

1 0.01

2 6.65556 ร— 10โˆ’5

3 2.65463 ร— 10โˆ’7

4 7.56708 ร— 10โˆ’10

5 1.67808 ร— 10โˆ’12

6 3.04791 ร— 10โˆ’15

Figure 1.2: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 6 by VIM.

1 2 3 4 5 6

10 13

10 10

10 7

10 4

n

ME

Rn

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Chapter One Primary Concepts

15

1.3.6 Pantograph differential equation

The pantograph is a type of delay differential equations. In 1971 Taylor

and Okondon developed first the mathematical model of the pantograph [46].

Pantograph equation used in many applications, such as industrial

applications [49], studies based on biology, economy, control and

electrodynamics [58]. In addition, the nonlinear dynamic systems and

population models. Consider the following generalized pantograph equation

[11].

๐‘ฃ(๐‘š)(๐‘ฅ) = โˆ‘ โˆ‘ ๐‘๐‘—๐‘˜(๐‘ฅ)๐‘ฃ(๐‘˜)(๐›ผ๐‘—๐‘ฅ + ๐›ฝ๐‘—) + ๐‘“(๐‘ฅ)

๐‘šโˆ’1

๐‘˜=0

๐ฝ

๐‘—=0

, (1.20)

with initial conditions

โˆ‘ ๐‘๐‘–๐‘˜๐‘ฃ(๐‘˜)(0) = ๐œ‡๐‘–

๐‘šโˆ’1

๐‘˜=0

, ๐‘– = 0, 1, โ€ฆ , ๐‘š โˆ’ 1,

where ๐‘๐‘—๐‘˜(๐‘ฅ) and ๐‘“(๐‘ฅ) are analytical functions, ๐ฝ โ‰ฅ 1, ๐‘๐‘–๐‘˜ , ๐œ‡๐‘– , ๐›ผ๐‘— and ๐›ฝ๐‘— are

real or complex constants.

Pantograph equation was solved by many authors either analytically or

numerically. For instance, Yusuf oglu [81] proposed an efficient algorithm for

solving generalized pantograph equations with the linear functional argument,

the authors of investigated an exponential approximation to obtain an

approximate solution of generalized pantograph-delay differential equations

[73]. High-order pantograph equations with initial conditions have been also

studied by Taylor method [62], ADM [14], DTM [78] and HPM [16].

Recently, Doha et al proposed and developed a new Jacobi rational-Gauss

collocation method for solving the generalized pantograph equations on a

semi-infinite domain [15].

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Chapter One Primary Concepts

16

1.3.7 VIM for solving the pantograph differential equation

Example 1.3 [11]:

Let us deal with the following pantograph differential equation,

๐‘ฃโ€ฒโ€ฒ =3

4๐‘ฃ + ๐‘ฃ (

๐‘ฅ

2) โˆ’ ๐‘ฅ2 + 2,

with the initial conditions ๐‘ฃ(0) = 0, ๐‘ฃ โ€ฒ(0) = 0. (1.21)

By using Eq. (1.14), we get:

๐‘ฃ๐‘›+1(๐‘ฅ) = ๐‘ฃ๐‘›(๐‘ฅ) + โˆซ [๐œ†(๐‘ ) (๐‘ฃ๐‘›โ€ฒโ€ฒ โˆ’

3

4๐‘ฃ๐‘› โˆ’ ๐‘ฃ๐‘› (

๐‘ 

2) โˆ’ ๐‘ 2 + 2)]

๐‘ฅ

0

๐‘‘๐‘ . (1.22)

Using the formula in Eq. (1.15) leads to ฮป = (๐‘  โˆ’ ๐‘ฅ). Substituting this value of

the Lagrange multiplier ฮป = (๐‘  โˆ’ ๐‘ฅ) into the functional Eq. (1.22) gives the

iteration formula:

๐‘ฃ๐‘›+1(๐‘ฅ) = ๐‘ฃ๐‘›(๐‘ฅ) + โˆซ [(๐‘  โˆ’ ๐‘ฅ) (๐‘ฃ๐‘›โ€ฒโ€ฒ โˆ’

3

4๐‘ฃ๐‘› โˆ’ ๐‘ฃ๐‘› (

๐‘ 

2) โˆ’ ๐‘ 2 + 2)]

๐‘ฅ

0

๐‘‘๐‘ ,

The initial approximation will be:

๐‘ฃ0(๐‘ฅ) = ๐‘ฃ(0) + ๐‘ฅ๐‘ฃโ€ฒ(0) = 0, (1.23)

By using Eq. (1.23), the following successive approximations will be obtained

๐‘ฃ0 = 0,

๐‘ฃ1 = ๐‘ฃ0 + โˆซ [(๐‘  โˆ’ ๐‘ฅ) (๐‘ฃ0โ€ฒโ€ฒ โˆ’

3

4๐‘ฃ0 โˆ’ ๐‘ฃ0 (

๐‘ 

2) โˆ’ ๐‘ 2 + 2)]

๐‘ฅ

0

๐‘‘๐‘  = ๐‘ฅ2 โˆ’๐‘ฅ4

12,

๐‘ฃ2 = ๐‘ฃ1 + โˆซ [(๐‘  โˆ’ ๐‘ฅ) (๐‘ฃ1โ€ฒโ€ฒ โˆ’

3

4๐‘ฃ1 โˆ’ ๐‘ฃ1 (

๐‘ 

2) โˆ’ ๐‘ 2 + 2)]

๐‘ฅ

0

๐‘‘๐‘  = ๐‘ฅ2 โˆ’13๐‘ฅ6

5760,

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Chapter One Primary Concepts

17

๐‘ฃ3 = ๐‘ฃ2 + โˆซ [(๐‘  โˆ’ ๐‘ฅ) (๐‘ฃ2โ€ฒโ€ฒ โˆ’

3

4๐‘ฃ2 โˆ’ ๐‘ฃ2 (

๐‘ 

2) โˆ’ ๐‘ 2 + 2)]

๐‘ฅ

0

๐‘‘๐‘ ,

= ๐‘ฅ2 โˆ’91๐‘ฅ8

2949120 ,

๐‘ฃ4 = ๐‘ฃ3 + โˆซ [(๐‘  โˆ’ ๐‘ฅ) (๐‘ฃ3โ€ฒโ€ฒ โˆ’

3

4๐‘ฃ3 โˆ’ ๐‘ฃ3 (

๐‘ 

2) โˆ’ ๐‘ 2 + 2)]

๐‘ฅ

0

๐‘‘๐‘ ,

= ๐‘ฅ2 โˆ’17563๐‘ฅ10

67947724800 ,

and so on. Then:

๐‘ฃ(๐‘ฅ) = ๐‘ฅ2 โˆ’ small term,

This series converges to the exact solution [11],

๐‘ฃ(๐‘ฅ) = ๐‘™๐‘–๐‘š๐‘›โ†’โˆž

๐‘ฃ๐‘›(๐‘ฅ) = ๐‘ฅ2.

1.3.8 Beam deformation equation

In the last two decades with the rapid development of applied science,

there has appeared mathematical model of the beam deformation equation

which is used in structural engineering and fluid mechanics.

Recently, many analytical methods are used to solve nonlinear beam

deformation equation, such as HPM [55], VIM [1], and ADM [25].

According to the classical beam theory in [1], the function ๐‘ฃ = ๐‘ฃ(๐‘ฅ)

represents the configuration of the deformed beam. The length of the beam is

๐ฟ = 1, where ๐‘ฅ = 0 at the left side and ๐‘ฅ = 1 at the right side and ๐‘“ = ๐‘“(๐‘ฅ) is

a load which causes the deformation [1], as it is shown in figure 1.3.

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Chapter One Primary Concepts

18

Let us consider the nonlinear beam deformation problem as a general

fourth order boundary value problem of the form [1],

๐‘ฃ(4)(๐‘ฅ) = ๐‘“(๐‘ฅ, ๐‘ฃ, ๐‘ฃโ€ฒ, ๐‘ฃ'', ๐‘ฃ'''), (1.24)

with the boundary conditions:

๐‘ฃ(๐‘Ž) = ๐›ผ1, ๐‘ฃโ€ฒ(๐‘Ž) = ๐›ผ2,

๐‘ฃ(๐‘) = ๐›ฝ1, ๐‘ฃโ€ฒ(๐‘) = ๐›ฝ2,

where ๐‘“ is a continuous function on [a,b] and the parameters ๐›ผ1,

๐›ผ2, ๐›ฝ1 and ๐›ฝ2 are finite real arbitrary constants. Eq. (1.24) used as

mathematical models in engineering.

Figure 1.3: Beam on the elastic bearing.

In this subsection, the following problem of the beam deformation will be

solved by using the VIM.

1.3.9 VIM for solving the nonlinear beam deformation problem

Example 1.4 [1]:

Let us consider the following form of the beam deformation equation,

๐‘ฃ(4) = ๐‘ฃ2 + ๐‘“(๐‘ฅ),

subject to the boundary conditions

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Chapter One Primary Concepts

19

๐‘ฃ(0) = 0, ๐‘ฃโ€ฒ(0) = 0, ๐‘ฃ(1) = 1, ๐‘ฃโ€ฒ(1) = 1. (1.25)

Where

๐‘“(๐‘ฅ) = โˆ’๐‘ฅ10 + 4๐‘ฅ9 โˆ’ 4๐‘ฅ8 โˆ’ 4๐‘ฅ7 + 8๐‘ฅ6 โˆ’ 4๐‘ฅ4 + 120๐‘ฅ โˆ’ 48,

By using Eq. (1.14), we have:

๐‘ฃ๐‘›+1(๐‘ฅ) = ๐‘ฃ๐‘›(๐‘ฅ) + โˆซ [๐œ†(๐‘ ) (๐‘ฃ๐‘›(4)

โˆ’ ๐‘ฃ๐‘›2 โˆ’ ๐‘“(๐‘ ))]

๐‘ฅ

0

๐‘‘๐‘ . (1.26)

By using the formula in Eq. (1.15) leads to ฮป = (๐‘ โˆ’๐‘ฅ)3

3!. Substituting this value

of the Lagrange multiplier ฮป = (๐‘ โˆ’๐‘ฅ)3

3! into the functional Eq. (1.26) gives the

iteration formula:

๐‘ฃ๐‘›+1(๐‘ฅ) = ๐‘ฃ๐‘›(๐‘ฅ) + โˆซ [(๐‘  โˆ’ ๐‘ฅ)3

3!(๐‘ฃ๐‘›

(4)โˆ’ ๐‘ฃ๐‘›

2 โˆ’ ๐‘“(๐‘ ))]๐‘ฅ

0

๐‘‘๐‘ . (1.27)

Let us assumed that an initial approximation has the form:

๐‘ฃ0(๐‘ฅ) = ๐‘Ž๐‘ฅ3 + ๐‘๐‘ฅ2 + ๐‘๐‘ฅ + ๐‘‘, (1.28)

where a, b, c, and d are unknown constants to be further determined.

By using the iteration formula (1.27), the following first-order approximation

is obtained:

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Chapter One Primary Concepts

20

๐‘ฃ1 = ๐‘ฃ0 + โˆซ [(๐‘  โˆ’ ๐‘ฅ)3

3!(๐‘ฃ0

(4)โˆ’ ๐‘ฃ0

2 โˆ’ ๐‘“(๐‘ ))]๐‘ฅ

0

๐‘‘๐‘ ,

= ๐‘‘ + ๐‘๐‘ฅ + ๐‘๐‘ฅ2 + ๐‘Ž๐‘ฅ3 + (โˆ’2 +๐‘‘2

24) ๐‘ฅ4 + (1 +

๐‘๐‘‘

60) ๐‘ฅ5

+ (๐‘2

360+

๐‘๐‘‘

180) ๐‘ฅ6 + (

๐‘๐‘

420+

๐‘Ž๐‘‘

420) ๐‘ฅ7

+ (โˆ’1

420+

๐‘2

1680+

๐‘Ž๐‘

840) ๐‘ฅ8 +

๐‘Ž๐‘๐‘ฅ9

1512+ (

1

630+

๐‘Ž2

5040) ๐‘ฅ10

โˆ’๐‘ฅ11

1980โˆ’

๐‘ฅ12

2970+

๐‘ฅ13

4290โˆ’

๐‘ฅ14

24024, (1.29)

Imposing the boundary conditions (1.25), into ๐‘ฃ1, results in the following

values:

๐‘Ž = โˆ’0.00687154, ๐‘ = 2.00593, ๐‘ = 0, ๐‘‘ = 0. (1.30)

The following first-order approximate solution is then achieved:

๐‘ฃ1 = 2.005929514398968๐‘ฅ2 โˆ’ 0.006871538792438514๐‘ฅ3 โˆ’ 2๐‘ฅ4

+ ๐‘ฅ5 + 0.00001413881948623746๐‘ฅ8

โˆ’ 0.000009116284704424509๐‘ฅ9

+ 0.001587310955961384๐‘ฅ10 โˆ’๐‘ฅ11

1980โˆ’

๐‘ฅ12

2970+

๐‘ฅ13

4290

โˆ’๐‘ฅ14

24024. (1.31)

Similarly, the following second-order approximation may be written:

๐‘ฃ2 = ๐‘ฃ1 + โˆซ [(๐‘  โˆ’ ๐‘ฅ)3

3!(๐‘ฃ1

(4)โˆ’ ๐‘ฃ1

2 โˆ’ ๐‘“(๐‘ ))]๐‘ฅ

0

๐‘‘๐‘ , (1.32)

Imposing the boundary conditions, (1.25), into ๐‘ฃ2, yields

๐‘Ž = โˆ’8.27907 ร— 10โˆ’7, ๐‘ = 2.000000763, ๐‘ = 0, ๐‘‘ = 0. (1.33)

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Chapter One Primary Concepts

21

The following second-order approximate solution is obtained:

๐‘ฃ2 = 2.0000007627556786๐‘ฅ2 โˆ’ 8.279069998454606 ร— 10โˆ’7๐‘ฅ3 โˆ’ 2๐‘ฅ4

+ ๐‘ฅ5 + 1.816085295168468 ร— 10โˆ’9๐‘ฅ8 โˆ’ โ‹ฏ. (1.34)

In order to check the accuracy of the approximate solution, we calculate

the absolute error, |๐‘Ÿ๐‘›| = |๐‘ฃ(๐‘ฅ) โˆ’ ๐‘ฃ๐‘›(๐‘ฅ)| where ๐‘ฃ(๐‘ฅ) = ๐‘ฅ5 โˆ’ 2๐‘ฅ4 + 2๐‘ฅ2 is

the exact solution and ๐‘ฃ๐‘›(๐‘ฅ) is the approximate solution. In table 1.3 the

absolute error of VIM with n = 1, 2 is presented.

Table 1.3: Results of the absolute errors for VIM.

x |๐’“๐Ÿ| for VIM |๐’“๐Ÿ| for VIM

0 0 0

0.1 5.24236 ร— 10โˆ’5 6.79965 ร— 10โˆ’9

0.2 1.82208 ร— 10โˆ’4 2.3887 ร— 10โˆ’8

0.3 3.48134 ร— 10โˆ’4 4.62946 ร— 10โˆ’8

0.4 5.09092 ร— 10โˆ’4 6.90558 ร— 10โˆ’8

0.5 6.24721 ร— 10โˆ’4 8.72068 ร— 10โˆ’8

0.6 6.57823 ร— 10โˆ’4 9.58101ร— 10โˆ’8

0.7 5.81138 ร— 10โˆ’4 9.01332 ร— 10โˆ’8

0.8 3.92709 ร— 10โˆ’4 6.67054 ร— 10โˆ’8

0.9 1.45715 ร— 10โˆ’4 2.80674 ร— 10โˆ’8

1.0 3.3447 ร— 10โˆ’8 0

It can be seen clearly from table 1.3, that by increasing the iterations, the

errors will decreasing.

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Chapter One Primary Concepts

22

1.4 Partial Differential Equations (PDEs)

PDE is an equation that contains the dependent variable, and its partial

derivatives. In the ordinary differential equations, the dependent variable ๐‘ฃ =

๐‘ฃ(๐‘ฅ) depends only on one independent variable x. Unlike the ODEs, the

dependent variable in the PDEs, such as ๐‘ฃ = ๐‘ฃ(๐‘ฅ, ๐‘ก) or ๐‘ฃ = ๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก), must

depend on more than one independent variable. If ๐‘ฃ = ๐‘ฃ(๐‘ฅ, ๐‘ก), then the

function ๐‘ฃ depends on the independent variable ๐‘ฅ, and on the time variable

๐‘ก [7]. In addition, it is well known that most of the phenomena that arise in

mathematical, chemical, physics and engineering fields can be described by

partial differential equations. For example, the heat flow and the wave

propagation phenomena, physical phenomena of fluid dynamics and many

other models described by partial differential equations.

In this section, we have examined the Burgersโ€™ equations governed by

nonlinear PDEs and will be introduced by using the ADM and the VIM.

1.4.1 Burgersโ€™ equation

The Burgers equation was first presented by Bateman [27] and treated

later by Johannes Martinus Burgers (1895-1981) then it is widely named as

Burgersโ€™ equation [45]. The introduction of the applications of Burgersโ€™

equations by mathematical scientists and researchers has become more

important and interesting, especially in problems that have the form of

nonlinear equations and systems of equations. It has been known that this

equation describes different types of phenomena such as modeling of

dynamics, heat conduction, acoustic waves and many others [5, 10, 36, 45,

61]. In addition, the 2D and 3D Burgersโ€™ equations have played an important

role in many physical applications such as modeling of gas dynamics and

shallow water waves [37, 48].

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Chapter One Primary Concepts

23

We consider the 1D, 2D and (1+3)-D Burgersโ€™ equations as follows [13,

76, 80],

๐œ•๐‘ฃ

๐œ•๐‘ก+ ๐‘ฃ

๐œ•๐‘ฃ

๐œ•๐‘ฅ= ๐‘˜ (

๐œ•2๐‘ฃ

๐œ•๐‘ฅ2) , 0 โ‰ค ๐‘ฅ โ‰ค 1, ๐‘ก > 0. (1.35)

๐œ•๐‘ฃ

๐œ•๐‘ก+ ๐‘ฃ

๐œ•๐‘ฃ

๐œ•๐‘ฅ+ ๐‘ฃ

๐œ•๐‘ฃ

๐œ•๐‘ฆ= ๐‘˜ (

๐œ•2๐‘ฃ

๐œ•๐‘ฅ2+

๐œ•2๐‘ฃ

๐œ•๐‘ฆ2) , 0 โ‰ค ๐‘ฅ, ๐‘ฆ โ‰ค 1, ๐‘ก > 0. (1.36)

๐œ•๐‘ฃ

๐œ•๐‘ก+ ๐‘ฃ

๐œ•๐‘ฃ

๐œ•๐‘ฅ= ๐‘˜ (

๐œ•2๐‘ฃ

๐œ•๐‘ฅ2+

๐œ•2๐‘ฃ

๐œ•๐‘ฆ2+

๐œ•2๐‘ฃ

๐œ•๐‘ง2) , 0 โ‰ค ๐‘ฅ, ๐‘ฆ, ๐‘ง โ‰ค 1, ๐‘ก > 0. (1.37)

In addition, the system of coupled Burgerโ€™s equation,

๐œ•๐‘ฃ

๐œ•๐‘กโˆ’ 2๐‘ฃ

๐œ•๐‘ฃ

๐œ•๐‘ฅ+

๐œ•(๐‘ฃ๐‘ข)

๐œ•๐‘ฅ=

1

๐‘…๐‘’(

๐œ•2๐‘ฃ

๐œ•๐‘ฅ2),

๐œ•๐‘ข

๐œ•๐‘กโˆ’ 2๐‘ข

๐œ•๐‘ข

๐œ•๐‘ฅ+

๐œ•(๐‘ฃ๐‘ข)

๐œ•๐‘ฅ=

1

๐‘…๐‘’(

๐œ•2๐‘ข

๐œ•๐‘ฅ2) , 0 โ‰ค ๐‘ฅ โ‰ค 1, ๐‘ก > 0, (1.38)

and the system of 2D Burgersโ€™ equation,

๐œ•๐‘ฃ

๐œ•๐‘ก+ ๐‘ฃ

๐œ•๐‘ฃ

๐œ•๐‘ฅ+ ๐‘ข

๐œ•๐‘ฃ

๐œ•๐‘ฆ=

1

๐‘…๐‘’(

๐œ•2๐‘ฃ

๐œ•๐‘ฅ2+

๐œ•2๐‘ฃ

๐œ•๐‘ฆ2),

๐œ•๐‘ข

๐œ•๐‘ก+ ๐‘ฃ

๐œ•๐‘ข

๐œ•๐‘ฅ+ ๐‘ข

๐œ•๐‘ข

๐œ•๐‘ฆ=

1

๐‘…๐‘’(

๐œ•2๐‘ข

๐œ•๐‘ฅ2+

๐œ•2๐‘ข

๐œ•๐‘ฆ2) , 0 โ‰ค ๐‘ฅ, ๐‘ฆ โ‰ค 1, ๐‘ก > 0, (1.39)

and the system of 3D Burgersโ€™ equation,

๐œ•๐‘ฃ

๐œ•๐‘ก+ ๐‘ข

๐œ•๐‘ฃ

๐œ•๐‘ฅ+ ๐‘ฃ

๐œ•๐‘ฃ

๐œ•๐‘ฆ+ ๐‘ค

๐œ•๐‘ฃ

๐œ•๐‘ง=

1

๐‘…๐‘’(

๐œ•2๐‘ฃ

๐œ•๐‘ฅ2+

๐œ•2๐‘ฃ

๐œ•๐‘ฆ2+

๐œ•2๐‘ฃ

๐œ•๐‘ง2),

๐œ•๐‘ข

๐œ•๐‘กโˆ’ ๐‘ข

๐œ•๐‘ข

๐œ•๐‘ฅโˆ’ ๐‘ฃ

๐œ•๐‘ข

๐œ•๐‘ฆโˆ’ ๐‘ค

๐œ•๐‘ข

๐œ•๐‘ง=

1

๐‘…๐‘’(

๐œ•2๐‘ฃ

๐œ•๐‘ฅ2+

๐œ•2๐‘ฃ

๐œ•๐‘ฆ2+

๐œ•2๐‘ฃ

๐œ•๐‘ง2),

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Chapter One Primary Concepts

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๐œ•๐‘ค

๐œ•๐‘ก+ ๐‘ข

๐œ•๐‘ค

๐œ•๐‘ฅ+ ๐‘ฃ

๐œ•๐‘ค

๐œ•๐‘ฆ+ ๐‘ค

๐œ•๐‘ค

๐œ•๐‘ง=

1

๐‘…๐‘’(

๐œ•2๐‘ฃ

๐œ•๐‘ฅ2+

๐œ•2๐‘ฃ

๐œ•๐‘ฆ2+

๐œ•2๐‘ฃ

๐œ•๐‘ง2),

0 โ‰ค ๐‘ฅ, ๐‘ฆ, ๐‘ง โ‰ค 1, ๐‘ก > 0, (1.40)

where k = 1

๐‘…๐‘’ is an arbitrary constant (Re: Reynolds number) for simulating

the physical phenomena of wave motion, and thus determines the behavior of

the solution. If the viscosity is k = 0, then the equation is called the equation

inviscid Burgersโ€™. It is the lowest approximation of the one-dimensional

system.

Recently, a number of researchers have solved the Burgersโ€™ equations.

For example, Marinca and Herisaun proposed the optimal homotopy

asymptotic method (OHAM) [66], Daftardar-Jafari method (DJM) in [32]. In

addition, considerable attention has been given to ADM for solving Burgersโ€™

equation [5]. Also, Laplace decomposition method (LDM) [60]. Moreover,

HPM was proposed by He [47], and many others [10, 61, 76].

1.4.2 Exact and numerical solutions for nonlinear Burgersโ€™

equation by ADM

In this subsection, the ADM is used to get an exact solution for the 1D

Burgersโ€™ equation and numerical solution for the 2D Burgersโ€™ equation. As

given in [7, 30].

Example 1.5 [33]:

Let us consider the following 1D Burgersโ€™ equation.

๐‘ฃ๐‘ก + ๐‘ฃ๐‘ฃ๐‘ฅ = ๐‘ฃ๐‘ฅ๐‘ฅ, with initial condition ๐‘ฃ(๐‘ฅ, 0) = 2๐‘ฅ. (1.41)

Applying the integration on both sides of Eq. (1.41) from 0 to ๐‘ก and

using the initial condition at ๐‘ฃ(๐‘ฅ, 0) = 2๐‘ฅ, we have

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Chapter One Primary Concepts

25

๐‘ฃ(๐‘ฅ, ๐‘ก) = 2๐‘ฅ + โˆซ (โˆ’๐‘ฃ๐‘ฃ๐‘ฅ+๐‘ฃ๐‘ฅ๐‘ฅ)๐‘‘๐‘ก. (1.42)๐‘ก

0

By using the decomposition series for the linear term ๐‘ฃ(๐‘ฅ, ๐‘ก) and the

series of Adomian polynomials for the nonlinear term ๐‘ฃ๐‘ฃ๐‘ฅ give

โˆ‘ ๐‘ฃ๐‘›(๐‘ฅ, ๐‘ก) = 2๐‘ฅ โˆ’ โˆซ (โˆ‘ ๐ด๐‘›

โˆž

๐‘›=0

) ๐‘‘๐‘ก๐‘ก

0

+ โˆซ (โˆ‘ ๐‘ฃ๐‘›๐‘ฅ๐‘ฅ

โˆž

๐‘›=0

) ๐‘‘๐‘ก. (1.43)๐‘ก

0

โˆž

๐‘›=0

Identifying the zeroth component ๐‘ฃ0(๐‘ฅ, ๐‘ก) by the term that arise from the

initial condition and following the decomposition method, we obtain the

recursive relation

๐‘ฃ0(๐‘ฅ, ๐‘ก) = 2๐‘ฅ,

๐‘ฃ๐‘›+1(๐‘ฅ, ๐‘ก) = โˆ’ โˆซ (โˆ‘ ๐ด๐‘›

โˆž

๐‘›=0

) ๐‘‘๐‘ก +๐‘ก

0

โˆซ (โˆ‘ ๐‘ฃ๐‘›๐‘ฅ๐‘ฅ

โˆž

๐‘›=0

) ๐‘‘๐‘ก,๐‘ก

0

๐‘› โ‰ฅ 0. (1.44)

The Adomian polynomials for the nonlinear term ๐‘ฃ๐‘ฃ๐‘ฅ have been derived in

the form

๐ด0 = ๐‘ฃ0๐‘ฅ๐‘ฃ0,

๐ด1 = ๐‘ฃ0๐‘ฅ๐‘ฃ1 + ๐‘ฃ1๐‘ฅ๐‘ฃ0,

๐ด2 = ๐‘ฃ0๐‘ฅ๐‘ฃ2 + ๐‘ฃ1๐‘ฅ๐‘ฃ1 + ๐‘ฃ2๐‘ฅ๐‘ฃ0,

๐ด3 = ๐‘ฃ0๐‘ฅ๐‘ฃ3 + ๐‘ฃ1๐‘ฅ๐‘ฃ2 + ๐‘ฃ2๐‘ฅ๐‘ฃ1 + ๐‘ฃ3๐‘ฅ๐‘ฃ0,

๐ด4 = ๐‘ฃ0๐‘ฅ๐‘ฃ4 + ๐‘ฃ1๐‘ฅ๐‘ฃ3 + ๐‘ฃ2๐‘ฅ๐‘ฃ2 + ๐‘ฃ3๐‘ฅ๐‘ฃ1,

โ‹ฎ

Consequently, we obtain:

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Chapter One Primary Concepts

26

๐‘ฃ0(๐‘ฅ, ๐‘ก) = 2๐‘ฅ,

๐‘ฃ1(๐‘ฅ, ๐‘ก) = โˆ’ โˆซ ๐ด0๐‘‘๐‘ก + โˆซ (๐‘ฃ0๐‘ฅ๐‘ฅ)๐‘‘๐‘ก = โˆ’4๐‘ก๐‘ฅ, ๐‘ก

0

๐‘ก

0

๐‘ฃ2(๐‘ฅ, ๐‘ก) = โˆ’ โˆซ ๐ด1๐‘‘๐‘ก + โˆซ (๐‘ฃ1๐‘ฅ๐‘ฅ)๐‘‘๐‘ก = 8๐‘ก2๐‘ฅ, ๐‘ก

0

๐‘ก

0

๐‘ฃ3(๐‘ฅ, ๐‘ก) = โˆ’ โˆซ ๐ด2๐‘‘๐‘ก + โˆซ (๐‘ฃ2๐‘ฅ๐‘ฅ)๐‘‘๐‘ก = โˆ’16๐‘ก3๐‘ฅ, ๐‘ก

0

๐‘ก

0

๐‘ฃ4(๐‘ฅ, ๐‘ก) = โˆ’ โˆซ ๐ด3๐‘‘๐‘ก + โˆซ (๐‘ฃ3๐‘ฅ๐‘ฅ)๐‘‘๐‘ก = 32๐‘ก4๐‘ฅ, ๐‘ก

0

๐‘ก

0

โ‹ฎ

Summing these iterates gives the series solution

๐‘ฃ(๐‘ฅ, ๐‘ก) = โˆ‘ ๐‘ฃ๐‘›(๐‘ฅ, ๐‘ก),

โˆž

๐‘›=0

= 2๐‘ฅ โˆ’ 4๐‘ฅ๐‘ก + 8๐‘ฅ๐‘ก2 โˆ’ 16๐‘ฅ๐‘ก3 + 32๐‘ฅ๐‘ก4 โˆ’ 64๐‘ฅ๐‘ก5 + 128๐‘ฅ๐‘ก6 โˆ’ 256๐‘ฅ๐‘ก7

+ 512๐‘ฅ๐‘ก8 โˆ’ โ‹ฏ,

This series converges to the exact solution [33]:

๐‘ฃ(๐‘ฅ, ๐‘ก) =2๐‘ฅ

1 + 2๐‘ก ,

= 2๐‘ฅ โˆ’ 4๐‘ฅ๐‘ก + 8๐‘ฅ๐‘ก2 โˆ’ 16๐‘ฅ๐‘ก3 + 32๐‘ฅ๐‘ก4 โˆ’ 64๐‘ฅ๐‘ก5 + 128๐‘ฅ๐‘ก6

โˆ’ 256๐‘ฅ๐‘ก7 + 512๐‘ฅ๐‘ก8 โˆ’ 1024๐‘ฅ๐‘ก9 + 2048๐‘ฅ๐‘ก10 โˆ’ โ‹ฏ.

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Chapter One Primary Concepts

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Example 1.6 [80]:

Consider the following 2D Burgersโ€™ equation,

๐‘ฃ๐‘ก + ๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ = ๐‘˜(๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ), ๐‘˜ > 0, (๐‘ฅ, ๐‘ฆ) โˆˆ [0,1] ร— [0,1], (1.45)

with initial condition ๐‘ฃ(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ).

Applying the integration on both sides of Eq. (1.45) from 0 to ๐‘ก and

using the initial condition at ๐‘ฃ(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ), we have

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)

+ โˆซ (โˆ’๐‘ฃ๐‘ฃ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฃ๐‘ฆ + ๐‘˜(๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ก. (1.46)๐‘ก

0

By using the decomposition series for the linear term ๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) and the

series of Adomian polynomials for the nonlinear term ๐‘ฃ๐‘ฃ๐‘ฅ, ๐‘ฃ๐‘ฃ๐‘ฆ give

โˆ‘ ๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก)

โˆž

๐‘›=0

= ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ) โˆ’ โˆซ (โˆ‘ ๐ด๐‘›

โˆž

๐‘›=0

) ๐‘‘๐‘ก ๐‘ก

0

โˆ’ โˆซ (โˆ‘ ๐ต๐‘›

โˆž

๐‘›=0

) ๐‘‘๐‘ก๐‘ก

0

+ โˆซ (โˆ‘ ๐‘˜(๐‘ฃ๐‘›๐‘ฅ๐‘ฅ +

โˆž

๐‘›=0

๐‘ฃ๐‘›๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ก, (1.47)๐‘ก

0

identifying the zeroth component ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก) by the term that arises from the

initial condition and following the ADM, we obtain the recursive relation

๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ),

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๐‘ฃ๐‘›+1(๐‘ฅ, ๐‘ฆ, ๐‘ก) = โˆ’ โˆซ (โˆ‘ ๐ด๐‘›

โˆž

๐‘›=0

) ๐‘‘๐‘ก๐‘ก

0

โˆ’ โˆซ (โˆ‘ ๐ต๐‘›

โˆž

๐‘›=0

) ๐‘‘๐‘ก +๐‘ก

0

โˆซ (โˆ‘ ๐‘˜(๐‘ฃ๐‘›๐‘ฅ๐‘ฅ +

โˆž

๐‘›=0

๐‘ฃ๐‘›๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ก๐‘ก

0

๐‘› โ‰ฅ 0. (1.48)

The Adomian polynomials for the nonlinear term ๐‘ฃ๐‘ฃ๐‘ฅ, ๐‘ฃ๐‘ฃ๐‘ฆ have been derived

in the form

๐ด0 = ๐‘ฃ0๐‘ฅ๐‘ฃ0,

๐ด1 = ๐‘ฃ0๐‘ฅ๐‘ฃ1 + ๐‘ฃ1๐‘ฅ๐‘ฃ0,

๐ด2 = ๐‘ฃ0๐‘ฅ๐‘ฃ2 + ๐‘ฃ1๐‘ฅ๐‘ฃ1 + ๐‘ฃ2๐‘ฅ๐‘ฃ0,

๐ด3 = ๐‘ฃ0๐‘ฅ๐‘ฃ3 + ๐‘ฃ1๐‘ฅ๐‘ฃ2 + ๐‘ฃ2๐‘ฅ๐‘ฃ1 + ๐‘ฃ3๐‘ฅ๐‘ฃ0,

and

๐ต0 = ๐‘ฃ0๐‘ฆ๐‘ฃ0,

๐ต1 = ๐‘ฃ0๐‘ฆ๐‘ฃ1 + ๐‘ฃ1๐‘ฆ๐‘ฃ0,

๐ต2 = ๐‘ฃ0๐‘ฆ๐‘ฃ2 + ๐‘ฃ1๐‘ฆ๐‘ฃ1 + ๐‘ฃ2๐‘ฆ๐‘ฃ0,

๐ต3 = ๐‘ฃ0๐‘ฆ๐‘ฃ3 + ๐‘ฃ1๐‘ฆ๐‘ฃ2 + ๐‘ฃ2๐‘ฆ๐‘ฃ1 + ๐‘ฃ3๐‘ฆ๐‘ฃ0,

consequently, we obtain:

๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ),

๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก) = โˆ’ โˆซ ๐ด0๐‘‘๐‘ก โˆ’ โˆซ ๐ต0๐‘‘๐‘ก + โˆซ ๐‘˜(๐‘ฃ0๐‘ฅ๐‘ฅ + ๐‘ฃ0๐‘ฆ๐‘ฆ)๐‘‘๐‘ก,๐‘ก

0

๐‘ก

0

๐‘ก

0

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Chapter One Primary Concepts

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= ๐‘ก(โˆ’8๐œ‹2๐‘˜๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ 2๐œ‹๐‘๐‘œ๐‘ (2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)2๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)

+ 2๐œ‹๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฆ)),

๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ก) = โˆ’ โˆซ ๐ด1๐‘‘๐‘ก โˆ’ โˆซ ๐ต1๐‘‘๐‘ก + โˆซ ๐‘˜(๐‘ฃ1๐‘ฅ๐‘ฅ + ๐‘ฃ1๐‘ฆ๐‘ฆ)๐‘‘๐‘ก,๐‘ก

0

๐‘ก

0

๐‘ก

0

= โˆ’2๐œ‹2๐‘ก2๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) + 32๐œ‹4๐‘ก2๐‘˜2๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) + โ‹ฏ,

๐‘ฃ3(๐‘ฅ, ๐‘ฆ, ๐‘ก) = โˆ’ โˆซ ๐ด2๐‘‘๐‘ก โˆ’ โˆซ ๐ต2๐‘‘๐‘ก + โˆซ ๐‘˜(๐‘ฃ2๐‘ฅ๐‘ฅ + ๐‘ฃ2๐‘ฆ๐‘ฆ)๐‘‘๐‘ก,๐‘ก

0

๐‘ก

0

๐‘ก

0

= 16๐œ‹4๐‘ก3๐‘˜๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’256

3๐œ‹6๐‘ก3๐‘˜3๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) + โ‹ฏ,

๐‘ฃ4(๐‘ฅ, ๐‘ฆ, ๐‘ก) = โˆ’ โˆซ ๐ด3๐‘‘๐‘ก โˆ’ โˆซ ๐ต3๐‘‘๐‘ก + โˆซ ๐‘˜(๐‘ฃ3๐‘ฅ๐‘ฅ + ๐‘ฃ3๐‘ฆ๐‘ฆ)๐‘‘๐‘ก,๐‘ก

0

๐‘ก

0

๐‘ก

0

=2

3๐œ‹4๐‘ก4๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ 64๐œ‹6๐‘ก4๐‘˜2๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) + โ‹ฏ,

then

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ 2๐œ‹2๐‘ก2๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)

+2

3๐œ‹4๐‘ก4๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) + 16๐œ‹4๐‘ก3๐‘˜๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)

+ 32๐œ‹4๐‘ก2๐‘˜2๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ โ‹ฏ.

The obtained series solution in Eq. (1.45) can be used to calculate the

maximal error remainder to show the highest accuracy level that we can

achieve. This can be clearly seen in table 1.4 and figure 1.4.

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Chapter One Primary Concepts

30

Table 1.4: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the ADM.

n ๐‘ด๐‘ฌ๐‘น๐’ by ADM

1 1.61705 ร— 10โˆ’2

2 2.98775 ร— 10โˆ’5

3 4.9464 ร— 10โˆ’8

4 7.1962 ร— 10โˆ’11

Figure 1.4: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 4 by ADM.

1.4.3 The VIM to solve the 2D Burgersโ€™ equation

In this subsection, the VIM is used to get a numerical solution for the 2D

Burgersโ€™ equation. As given in [50].

Example 1.7 [80]:

Rewrite the example 1.6 and solve it by VIM,

๐‘ฃ๐‘ก + ๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ = ๐‘˜(๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ), (1.49)

with initial condition ๐‘ฃ(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ).

By using Eq. (1.14), we get:

1.0 1.5 2.0 2.5 3.0 3.5 4.0

10 8

10 5

10 2

n

ME

Rn

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Chapter One Primary Concepts

31

๐‘ฃ๐‘›+1(๐‘ฅ, ๐‘ฆ, ๐‘ก)

= ๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก)

+ โˆซ [๐œ†(๐‘ )(๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘  + ๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฅ

๐‘ก

0

+ ๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฆ โˆ’ ๐‘˜(๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฅ๐‘ฅ

+ ๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฆ๐‘ฆ))] ๐‘‘๐‘ . (1.50)

Using Eq. (1.15) leads to ฮป = โˆ’1. Substituting this value of the Lagrange

multiplier into the functional Eq. (1.50) gives the following iteration formula:

๐‘ฃ๐‘›+1(๐‘ฅ, ๐‘ฆ, ๐‘ก)

= ๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก)

โˆ’ โˆซ (๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘  + ๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฅ

๐‘ก

0

+ ๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฆ โˆ’ ๐‘˜(๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฅ๐‘ฅ

+ ๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ )๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ . (1.51)

By applying Mathematicaโ€™s code (see appendix B), we get the following

initial approximation

๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฃ(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ),

By using Eq. (1.51) the obtained successive approximations will be

๐‘ฃ0 = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ),

๐‘ฃ1 = ๐‘ฃ0 โˆ’ โˆซ (๐‘ฃ0๐‘ + ๐‘ฃ0๐‘ฃ0๐‘ฅ

+ ๐‘ฃ0๐‘ฃ0๐‘ฆโˆ’ ๐‘˜(๐‘ฃ0๐‘ฅ๐‘ฅ

+ ๐‘ฃ0๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ ,

๐‘ก

0

= ๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ ๐‘ก(8๐œ‹2๐‘˜๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)

+ 2๐œ‹๐‘๐‘œ๐‘ (2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)2๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ 2๐œ‹๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฆ)),

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Chapter One Primary Concepts

32

๐‘ฃ2 = ๐‘ฃ1 โˆ’ โˆซ (๐‘ฃ1๐‘ + ๐‘ฃ1๐‘ฃ1๐‘ฅ

+ ๐‘ฃ1๐‘ฃ1๐‘ฆโˆ’ ๐‘˜(๐‘ฃ1๐‘ฅ๐‘ฅ

+ ๐‘ฃ1๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ ,

๐‘ก

0

= ๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ 2๐œ‹2๐‘ก2๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)

+ 32๐œ‹4๐‘ก2๐‘˜2๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)

+ 40๐œ‹3๐‘ก2๐‘˜๐‘๐‘œ๐‘ (2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)2๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ โ‹ฏ,

continuing in this way till n = 6, we have

๐‘ฃ6 = ๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ 2๐œ‹2๐‘ก2๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)

+2

3๐œ‹4๐‘ก4๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) + โ‹ฏ, (1.52)

Table 1.5 and Figure 1.5 illustrate the convergence of the solution

through the use of the maximal error remainder. Clearly seen, the errors will

be decreased as the number of iterations will be increased.

Table 1.5: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the VIM.

n ๐‘ด๐‘ฌ๐‘น๐’ by VIM

1 1.61705 ร— 10โˆ’2

2 2.52036 ร— 10โˆ’5

3 3.56783 ร— 10โˆ’8

4 4.53593 ร— 10โˆ’11

Figure 1.5: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 4 by V1M.

1.0 1.5 2.0 2.5 3.0 3.5 4.010 11

10 8

10 5

10 2

n

ME

Rn

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CHAPTER 2

SEMI-ANALYTICAL

ITERATIVE METHOD FOR

SOLVING SOME ORDINARY

AND PARTIAL DIFFERENTIAL

EQUATIONS

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

33

Chapter 2

Semi-Analytical Iterative Method for Solving Some

Ordinary and Partial Differential Equations

2.1 Introduction

Temimi and Ansari have proposed recently a semi-analytical iterative

method namely (TAM) to solve various linear and nonlinear ODEs and PDEs

[28]. For examples, solving nonlinear ordinary differential equations [29], the

Korteweg-de Vries Equations [18], Duffing equations [51], the nonlinear thin

film flow problems [53], and some chemistry problems [52].

The main advantages of the TAM, it does not required any restrictive

assumptions for nonlinear terms since the ADM required the so-called

Adomian polynomial, avoided the large computational work or using any

other parameters or restricted assumptions that appear in other iterative

methods such as VIM and HPM. In addition, the TAM for solving non-linear

ODEs and PDEs have successfully implemented.

This chapter is organized as follows: in section two, the basic idea of the

TAM is presented. In section three, an overview of the convergence of the

TAM based on the Banach fixed-point theorem will be given. In section four,

some types of non-linear ODEs equations will be solved by TAM, namely the

Riccati equation, pantograph equation and beam deformation equation.

Moreover, the Burgersโ€™ equations will be solved and the convergence will be

proved.

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

34

2.2 The basic idea of the TAM

We start by pointing out that the nonlinear differential equation can be

written in operator form as:

๐ฟ(๐‘ฃ(๐‘ฅ)) + ๐‘(๐‘ฃ(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0, ๐‘ฅ โˆˆ ๐ท,

with boundary conditions ๐ต(๐‘ฃ, ๐‘‘๐‘ฃ

๐‘‘๐‘ฅ ) = 0, ๐‘ฅ โˆˆ ๐œ‡. (2.1)

Where x denotes the independent variable, ๐‘ฃ(๐‘ฅ) is an unknown function,

๐‘“(๐‘ฅ) is a known function, ๐œ‡ is the boundary of the domain ๐ท, ๐ฟ is a linear

operator, ๐‘ is a nonlinear operator and ๐ต is a boundary operator. The main

requirement here is that ๐ฟ is the linear part of the differential equation, but it

is possible to take some linear parts and add them to ๐‘ as needed. The method

works in the following steps, starts by assuming that ๐‘ฃ0(๐‘ฅ) is an initial guess

of the solution to the problem [28].

๐ฟ(๐‘ฃ0(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0, ๐ต(๐‘ฃ0, ๐‘‘๐‘ฃ0๐‘‘๐‘ฅ

) = 0. (2.2)

To generate the next iteration of the solution, we solve the following

problem:

๐ฟ(๐‘ฃ1(๐‘ฅ)) + ๐‘(๐‘ฃ0(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0, ๐ต(๐‘ฃ1, ๐‘‘๐‘ฃ1๐‘‘๐‘ฅ

) = 0. (2.3)

Thus, we have a simple iterative procedure which is effectively the

solution of a linear set of problems i.e.

๐ฟ(๐‘ฃ๐‘›+1(๐‘ฅ)) + ๐‘(๐‘ฃ๐‘›(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0, ๐ต(๐‘ฃ๐‘›+1, ๐‘‘๐‘ฃ๐‘›+1๐‘‘๐‘ฅ

) = 0. (2.4)

It is noted that each of the ๐‘ฃ๐‘›(๐‘ฅ), are solutions to Eq. (2.1). Thus,

evaluating more approximate terms provides better accuracy.

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

35

2.3 The convergence of the TAM

The Banach fixed-point theorem also known as the contraction mapping

principle is an important tool in the theory of metric spaces. It guarantees the

existence and uniqueness of fixed points of certain self-maps of metric spaces.

Also, provides a constructive method to find those fixed points. The theorem

is named after Stefan Banach (1892โ€“1945), and was first stated by him in

1922 [69]. In this section, some basic concepts and the main theorem of the

convergence will be presented.

Theorem 2.1: [33]

Suppose that (๐‘‹, โ€– โ€–๐‘‹) and (๐‘Œ, โ€– โ€–๐‘Œ) be Banach spaces and T: X โ†’ Y, is

a contraction nonlinear mapping, that is

โˆ€ ๐‘ฃ, ๐‘ฃโˆ— โˆˆ ๐‘‹ ; โ€–๐‘‡(๐‘ฃ) โˆ’ ๐‘‡(๐‘ฃโˆ—)โ€–๐‘‹ โ‰ค ๐‘˜โ€–๐‘ฃ โˆ’ ๐‘ฃโˆ—โ€–๐‘Œ, 0 < ๐‘˜ < 1.

According to theorem 1.1, having the fixed point ๐‘ฃ, that is ๐‘‡(๐‘ฃ) = ๐‘ฃ, the

sequence generated by the TAM will be regarded as

๐‘ฃ๐‘› = ๐‘‡(๐‘ฃ๐‘›โˆ’1), ๐‘ฃ = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›,

and suppose that ๐‘ฃ0 โˆˆ ๐ต๐‘Ÿ(๐‘ฃ) where ๐ต๐‘Ÿ(๐‘ฃ) = {๐‘ฃโˆ— โˆˆ ๐‘‹, โ€–๐‘ฃโˆ— โˆ’ ๐‘ฃโ€– < ๐‘Ÿ} then

we have the following statements:

1. โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘›โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

2. ๐‘ฃ๐‘› โˆˆ ๐ต๐‘Ÿ(๐‘ฃ),

3. ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› = ๐‘ฃ,

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

36

2.4 Application of the TAM with convergence for the ODE

and PDE

In this section, some types of non-linear ODEs equations will be solved

by TAM, namely the Riccati equation, pantograph equation and beam

deformation equation. Moreover, the Burgersโ€™ equations will be solved and

the convergence will be proved.

2.4.1 Exact and numerical solutions for nonlinear Riccati

equation by TAM

The TAM will be implemented to solve the Riccati differential equation

which is a nonlinear ODE of first order. So, to verify the accuracy of the

TAM in solving this kind of problems, the following examples will be

discussed.

Example 2.1 [19]:

Let us consider the following Riccati differential equation,

๐‘ฃโ€ฒ = โ…‡๐‘ฅ โˆ’ โ…‡3๐‘ฅ + 2โ…‡2๐‘ฅ๐‘ฃ โˆ’ โ…‡๐‘ฅ๐‘ฃ2, with initial condition ๐‘ฃ(0) = 1. (2.5)

By applying the TAM by first distributing the equation as,

๐ฟ(๐‘ฃ) = ๐‘ฃโ€ฒ, ๐‘(๐‘ฃ) = โˆ’2โ…‡2๐‘ฅ๐‘ฃ + โ…‡๐‘ฅ๐‘ฃ2 and ๐‘“(๐‘ฅ) = โˆ’โ…‡๐‘ฅ + โ…‡3๐‘ฅ.

Thus, the initial problem will be

๐ฟ(๐‘ฃ0(๐‘ฅ)) = โ…‡๐‘ฅ โˆ’ โ…‡3๐‘ฅ, ๐‘ฃ0(0) = 1. (2.6)

By integrating both sides of Eq. (2.6) from 0 to x, we obtain

โˆซ ๐‘ฃ0โ€ฒ (๐‘ก) โ…†๐‘ก

๐‘ฅ

0

= โˆซ (โ…‡๐‘ก โˆ’ โ…‡3๐‘ก) โ…†๐‘ก, ๐‘ฃ0(0) = 1.๐‘ฅ

0

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

37

Therefore, we have

๐‘ฃ0(๐‘ฅ) =1

3+ โ…‡๐‘ฅ โˆ’

โ…‡3๐‘ฅ

3.

The second iteration can be given as

๐ฟ(๐‘ฃ1(๐‘ฅ)) + ๐‘(๐‘ฃ0(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0, ๐‘ฃ1(0) = 1. (2.7)

By using simple manipulation, one can solve Eq. (2.7) as follows:

โˆซ ๐‘ฃ1โ€ฒ (๐‘ก) โ…†๐‘ก

๐‘ฅ

0

= โˆซ (โ…‡๐‘ก โˆ’ โ…‡3๐‘ก + 2โ…‡2๐‘ก๐‘ฃ0(๐‘ก) โˆ’ โ…‡๐‘ก๐‘ฃ02(๐‘ก)) โ…†๐‘ก, ๐‘ฃ1(0) = 1.

๐‘ฅ

0

Then, we obtain

๐‘ฃ1(๐‘ฅ) =1

14+

8โ…‡๐‘ฅ

9+

โ…‡4๐‘ฅ

18โˆ’

โ…‡7๐‘ฅ

63.

We turn the function ๐‘ฃ1(๐‘ฅ) by using Maclaurin series expansion to

exponential function, we get

๐‘ฃ1(๐‘ฅ) = 1 + ๐‘ฅ +๐‘ฅ2

2โˆ’

๐‘ฅ3

6โˆ’

23๐‘ฅ4

24โˆ’

209๐‘ฅ5

120.

Applying the same process, we get the second iteration ๐‘ฃ2(๐‘ฅ),

๐ฟ(๐‘ฃ2(๐‘ฅ)) + ๐‘(๐‘ฃ1(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0, ๐‘ฃ2(0) = 1.

Then, we have

๐‘ฃ2(๐‘ฅ) =11

9720+

195โ…‡๐‘ฅ

196+

โ…‡2๐‘ฅ

126โˆ’

โ…‡3๐‘ฅ

243โˆ’

โ…‡5๐‘ฅ

630+

โ…‡6๐‘ฅ

486+

โ…‡8๐‘ฅ

3528โˆ’

5โ…‡9๐‘ฅ

6804

+โ…‡12๐‘ฅ

6804โˆ’

โ…‡15๐‘ฅ

59535.

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

38

We can write the function ๐‘ฃ2(๐‘ฅ) in the following series form,

๐‘ฃ2(๐‘ฅ) = 1 + ๐‘ฅ +๐‘ฅ2

2+

๐‘ฅ3

6+

๐‘ฅ4

24+

๐‘ฅ5

120+

๐‘ฅ6

720โˆ’

79๐‘ฅ7

5040โˆ’

3919๐‘ฅ8

40320

โˆ’116479๐‘ฅ9

362880.

By continuing in this way, we will get a series of the form:

๐‘ฃ(๐‘ฅ) = ๐‘™๐‘–๐‘š๐‘›โ†’โˆž

๐‘ฃ๐‘›(๐‘ฅ) = 1 + ๐‘ฅ +๐‘ฅ2

2+

๐‘ฅ3

6+

๐‘ฅ4

24+

๐‘ฅ5

120+ โ‹ฏ,

This series converges to the following exact solution [19].

๐‘ฃ(๐‘ฅ) = โ…‡๐‘ฅ = 1 + ๐‘ฅ +๐‘ฅ2

2+

๐‘ฅ3

6+

๐‘ฅ4

24+

๐‘ฅ5

120+

๐‘ฅ6

720+ โ‹ฏ.

Suppose that T: [0,1] โ†’ ๐‘…, then ๐‘ฃ๐‘› = ๐‘‡(๐‘ฃ๐‘›โˆ’1) and 0 โ‰ค ๐‘ฅ โ‰ค 1.

According to the theorem 2.1 for nonlinear mapping T, a sufficient

condition for convergence of the TAM is strictly contraction T, the exact

solution is ๐‘ฃ = ๐‘ฃ(๐‘ฅ) = โ…‡๐‘ฅ, therefore, we have

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = โ€–1

3+ โ…‡๐‘ฅ โˆ’

โ…‡3๐‘ฅ

3โˆ’ โ…‡๐‘ฅโ€–,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– = โ€–1

14+

8โ…‡๐‘ฅ

9+

โ…‡4๐‘ฅ

18โˆ’

โ…‡7๐‘ฅ

63โˆ’ โ…‡๐‘ฅโ€– โ‰ค ๐‘˜ โ€–

1

3+ โ…‡๐‘ฅ โˆ’

โ…‡3๐‘ฅ

3โˆ’ โ…‡๐‘ฅโ€–

= ๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

But, โˆ€ ๐‘ฅ ๐œ– [0,1], 0 < ๐‘˜ < 1, when ๐‘ฅ = 1

2,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.19551 < 1,

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

39

Then, we have

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜ โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– = โ€–11

9720+

195โ…‡๐‘ฅ

196+

โ…‡2๐‘ฅ

126โˆ’

โ…‡3๐‘ฅ

243โˆ’

โ…‡5๐‘ฅ

630+

โ…‡6๐‘ฅ

486+

โ…‡8๐‘ฅ

3528โˆ’

5โ…‡9๐‘ฅ

6804+

โ…‡12๐‘ฅ

6804โˆ’

โ…‡15๐‘ฅ

59535โˆ’ โ…‡๐‘ฅโ€– โ‰ค ๐‘˜โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Since, โˆ€ ๐‘ฅ ๐œ– [0,1], 0 < ๐‘˜ < 1, when ๐‘ฅ =1

2,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 โ‡’ โˆš

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.0580412 < 1,

Thus, we get

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Similarly, we have

โ€–๐‘ฃ3 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜3โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

By continuing in this way, we get:

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘›โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Therefore,

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = 0, and ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› = 0, we drive

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– =0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› = ๐‘ฃ = โ…‡๐‘ฅ, which is the exact solution [19].

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

40

Example 2.2:

Let us recall example 1.1

๐‘ฃโ€ฒ = โˆ’๐‘ฃ2 + 1, with initial condition ๐‘ฃ(0) = 0. (2.8)

By applying the TAM by first distributing the equation as

๐ฟ(๐‘ฃ) = ๐‘ฃโ€ฒ, ๐‘(๐‘ฃ) = ๐‘ฃ2 and ๐‘“(๐‘ฅ) = โˆ’1

Thus, the initial problem will be

๐ฟ(๐‘ฃ0(๐‘ฅ)) = 1, ๐‘ฃ0(0) = 0, (2.9)

By integrating both sides of Eq. (2.9) from 0 to x, we have

โˆซ ๐‘ฃ0โ€ฒ (๐‘ก) โ…†๐‘ก

๐‘ฅ

0

= โˆซ (1) โ…†๐‘ก, ๐‘ฃ0(0) = 0,๐‘ฅ

0

So, we get

๐‘ฃ0(๐‘ฅ) = ๐‘ฅ.

The second iteration can be given as

๐ฟ(๐‘ฃ1(๐‘ฅ)) + ๐‘(๐‘ฃ0(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0, ๐‘ฃ1(0) = 0, (2.10)

By using simple manipulation, one can solve Eq. (2.10) as follows

โˆซ ๐‘ฃ1โ€ฒ (๐‘ก) โ…†๐‘ก

๐‘ฅ

0

= โˆซ (โˆ’๐‘ฃ02(๐‘ก) + 1) โ…†๐‘ก, ๐‘ฃ1(0) = 0.

๐‘ฅ

0

Then, we obtain

๐‘ฃ1(๐‘ฅ) = ๐‘ฅ โˆ’๐‘ฅ3

3.

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

41

Applying the same process to get the second iteration ๐‘ฃ2(๐‘ฅ),

๐ฟ(๐‘ฃ2(๐‘ฅ)) + ๐‘(๐‘ฃ1(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0, ๐‘ฃ2(0) = 0,

We have

๐‘ฃ2(๐‘ฅ) = ๐‘ฅ โˆ’๐‘ฅ3

3+

2๐‘ฅ5

15โˆ’

๐‘ฅ7

63.

Continuing in this way till n = 6, but for brevity, they are not listed.

The obtained series solution in Eq. (2.8) can be used to calculate the

maximal error remainder to show the highest accuracy level that we can

achieve. This can be clearly seen in table 2.1 and figure 2.1

Table 2.1: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the TAM.

n ๐‘ด๐‘ฌ๐‘น๐’ by TAM

1 6.65556 ร— 10โˆ’5

2 2.65463 ร— 10โˆ’7

3 7.56708 ร— 10โˆ’10

4 1.67806 ร— 10โˆ’12

5 2.97852 ร— 10โˆ’15

6 1.24033 ร— 10โˆ’16

Figure 2.1: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 6 by TAM.

1 2 3 4 5 6

10 15

10 12

10 9

10 6

n

ME

Rn

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

42

2.4.2 TAM for solving linear pantograph equation

In this subsection, the TAM will be applied for second order linear

pantograph equation which is used in many applications, such as industrial

applications, studies based on biology, economy and others. The following

example presents a solution for pantograph equation by using the TAM.

Example 2.3 [11]:

Resolve example 1.3 by using TAM.

๐‘ฃโ€ฒโ€ฒ =3

4๐‘ฃ + ๐‘ฃ (

๐‘ฅ

2) โˆ’ ๐‘ฅ2 + 2,

with initial conditions ๐‘ฃ(0) = 0 , ๐‘ฃโ€ฒ(0) = 0. (2.11)

To solve Eq. (2.11) by TAM, distribute the equation as follows

๐ฟ(๐‘ฃ) = ๐‘ฃ", ๐‘(๐‘ฃ) = โˆ’3

4๐‘ฃ โˆ’ ๐‘ฃ(

๐‘ฅ

2) and ๐‘“(๐‘ฅ) = ๐‘ฅ2 โˆ’ 2.

Thus, the initial problem which needs to be solved is

๐ฟ(๐‘ฃ0(๐‘ฅ)) = โˆ’๐‘ฅ2 + 2, ๐‘ฃ0(0) = 0, ๐‘ฃ0โ€ฒ(0) = 0. (2.12)

Integrate both sides of Eq. (2.12) twice from 0 to x and substitute the initial

conditions, we get

โˆซ โˆซ ๐‘ฃ0โ€ฒโ€ฒ(๐‘ก)โ…†๐‘กโ…†๐‘ก

๐‘ฅ

0

๐‘ฅ

0

= โˆซ โˆซ (โˆ’๐‘ก2 + 2)โ…†๐‘กโ…†๐‘ก๐‘ฅ

0

๐‘ฅ

0

, ๐‘ฃ0(0) = 0, ๐‘ฃ0โ€ฒ(0) = 0.

Then, we obtain

๐‘ฃ0(๐‘ฅ) = ๐‘ฅ2 โˆ’๐‘ฅ4

12.

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

43

The second iteration can be carried as

๐ฟ(๐‘ฃ1(๐‘ฅ)) + ๐‘(๐‘ฃ0(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0, ๐‘ฃ1(0) = 0, ๐‘ฃ1โ€ฒ(0) = 0. (2.13)

By integrating both sides of Eq. (2.13) twice from 0 to ๐‘ฅ, we obtain

โˆซ โˆซ ๐‘ฃ1โ€ฒโ€ฒ(๐‘ก) โ…†๐‘กโ…†๐‘ก

๐‘ฅ

0

๐‘ฅ

0

= โˆซ โˆซ (โˆ’๐‘ก2 + 2 +3

4๐‘ฃ0(๐‘ก) + ๐‘ฃ0 (

๐‘ก

2)) โ…†๐‘กโ…†๐‘ก,

๐‘ฅ

0

๐‘ฅ

0

with initial conditions ๐‘ฃ1(0) = 0, ๐‘ฃ1โ€ฒ(0) = 0.

Thus, we get

๐‘ฃ1(๐‘ฅ) = ๐‘ฅ2 โˆ’13๐‘ฅ6

5760.

The next iteration is

๐ฟ(๐‘ฃ2(๐‘ฅ)) + ๐‘(๐‘ฃ1(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0 , ๐‘ฃ2(0) = 0, ๐‘ฃ2โ€ฒ(0) = 0.

Thus, we have

๐‘ฃ2(๐‘ฅ) = ๐‘ฅ2 โˆ’91๐‘ฅ8

2949120 .

The next iteration is

๐ฟ(๐‘ฃ3(๐‘ฅ)) + ๐‘(๐‘ฃ2(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0, ๐‘ฃ3(0) = 0, ๐‘ฃ3โ€ฒ(0) = 0.

Then, we get

๐‘ฃ3(๐‘ฅ) = ๐‘ฅ2 โˆ’17563๐‘ฅ10

67947724800 .

By continuing in this way, we will get:

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

44

๐‘ฃ(๐‘ฅ) = ๐‘ฅ2 โˆ’ small term,

This series converges to the exact solution [11]:

๐‘ฃ(๐‘ฅ) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ) = ๐‘ฅ2.

Suppose that ๐‘‡: [0,1] โ†’ ๐‘…, then ๐‘ฃ๐‘› = ๐‘‡(๐‘ฃ๐‘›โˆ’1) and 0 โ‰ค ๐‘ฅ โ‰ค 1.

Following the same procedure as for the Riccati equation, the exact solution

for pantograph equation is ๐‘ฃ = ๐‘ฃ(๐‘ฅ) = ๐‘ฅ2, therefore, we have

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฅ2 โˆ’๐‘ฅ4

12โˆ’ (๐‘ฅ2)โ€–,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฅ2 โˆ’13๐‘ฅ6

5760โˆ’ (๐‘ฅ2)โ€– โ‰ค ๐‘˜ โ€–๐‘ฅ2 โˆ’

๐‘ฅ4

12โˆ’ (๐‘ฅ2)โ€– = ๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

But, โˆ€ ๐‘ฅ ๐œ– [0,1], 0 < ๐‘˜ < 1, when ๐‘ฅ = 1

4,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.00169271 < 1,

Then, we have

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜ โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฅ2 โˆ’91๐‘ฅ8

2949120โˆ’ (๐‘ฅ2)โ€– โ‰ค ๐‘˜โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– =

๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Since, โˆ€ ๐‘ฅ ๐œ– [0,1], 0 < ๐‘˜ < 1, when ๐‘ฅ =1

4,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 โ‡’ โˆš

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.00120267 < 1,

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

45

Thus, we get

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Similarly, we have

โ€–๐‘ฃ3 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜3โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

By continuing in this way, we get:

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘›โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Therefore,

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = 0 , and ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› = 0, then

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– =0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› = ๐‘ฃ = ๐‘ฅ2, which is the exact solution [11].

2.4.3 Solving the nonlinear beam equation by using the TAM

In this subsection, the TAM will be implemented to solve fourth order

nonlinear beam deformation problem which is a boundary value problems that

are considered one of more important equations because they are widely used

in different scientific specializations. These boundary value problems appear

in applied mathematics, engineering, several branches of physics and others.

Example 2.4:

Let us recall example 1.4

๐‘ฃ(4) = ๐‘ฃ2 โˆ’ ๐‘ฅ10 + 4๐‘ฅ9 โˆ’ 4๐‘ฅ8 โˆ’ 4๐‘ฅ7 + 8๐‘ฅ6 โˆ’ 4๐‘ฅ4 + 120๐‘ฅ โˆ’ 48,

with boundary conditions ๐‘ฃ(0) = ๐‘ฃโ€ฒ(0) = 0, ๐‘ฃ(1) = ๐‘ฃโ€ฒ(1) = 1. (2.14)

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Chapter Two Semi-Analytical Iterative Method for Solving

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46

By applying the TAM for Eq. (2.14), we get

๐ฟ(๐‘ฃ) = ๐‘ฃ(4), ๐‘(๐‘ฃ) = โˆ’๐‘ฃ2,

๐‘“(๐‘ฅ) = ๐‘ฅ10 โˆ’ 4๐‘ฅ9 + 4๐‘ฅ8 + 4๐‘ฅ7 โˆ’ 8๐‘ฅ6 + 4๐‘ฅ4 โˆ’ 120๐‘ฅ + 48.

Thus, the initial problem which needs to be solved is

๐ฟ(๐‘ฃ0(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0, ๐‘ฃ0(0) = ๐‘ฃ0โ€ฒ(0) = 0, ๐‘ฃ0(1) = ๐‘ฃ0โ€ฒ(1) = 1. (2.15)

By integrating both sides of (2.15) from 0 to ๐‘ฅ four times, one can obtain

โˆซ โˆซ โˆซ โˆซ ๐‘ฃ0(4)(๐‘ก) โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

= โˆซ โˆซ โˆซ โˆซ โˆ’๐‘“(๐‘ก) โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก,๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

Then, we have

๐‘ฃ0(๐‘ฅ) = ๐‘ฃ0(0) + ๐‘ฅ๐‘ฃ0โ€ฒ (0) +

๐‘ฅ2

2๐‘ฃ0

โ€ฒโ€ฒ(0) + ๐‘ฅ3

6๐‘ฃ0

โ€ฒโ€ฒโ€ฒ(0)

โˆ’ โˆซ โˆซ โˆซ โˆซ ๐‘“(๐‘ก) โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก, ๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

(2.16)

Imposing the boundary conditions (2.15), into Eq. (2.16), and by applying

Mathematicaโ€™s code, see appendix C, the results are as follows.

๐‘ฃ0(๐‘ฅ) =718561๐‘ฅ2

360360+

4019๐‘ฅ3

540540โˆ’ 2๐‘ฅ4 + ๐‘ฅ5 โˆ’

๐‘ฅ8

420+

๐‘ฅ10

630โˆ’

๐‘ฅ11

1980โˆ’

๐‘ฅ12

2970

+๐‘ฅ13

4290โˆ’

๐‘ฅ14

24024.

The second iteration can be carried through and we have

๐ฟ(๐‘ฃ1(๐‘ฅ)) + ๐‘(๐‘ฃ0(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0,

๐‘ฃ1(0) = ๐‘ฃ1โ€ฒ(0) = 0, ๐‘ฃ1(1) = ๐‘ฃ1โ€ฒ(1) = 1. (2.17)

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

47

By integrating both sides of (2.17) from 0 to ๐‘ฅ four times, one can obtain

โˆซ โˆซ โˆซ โˆซ ๐‘ฃ1(4)(๐‘ก) โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

= โˆซ โˆซ โˆซ โˆซ (๐‘ฃ02(๐‘ก) โˆ’ ๐‘“(๐‘ก)) โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก,

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

Then, we have

๐‘ฃ1(๐‘ฅ) = ๐‘ฃ1(0) + ๐‘ฅ๐‘ฃ1โ€ฒ (0) +

๐‘ฅ2

2๐‘ฃ1

โ€ฒโ€ฒ(0) + ๐‘ฅ3

6๐‘ฃ1

โ€ฒโ€ฒโ€ฒ(0)

+ โˆซ โˆซ โˆซ โˆซ (๐‘ฃ02(๐‘ก) โˆ’ ๐‘“(๐‘ก)) โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก โ…†๐‘ก,

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

(2.18)

Similarly, by imposing the boundary conditions (2.17), into Eq. (2.18), the

results are as follows:

๐‘ฃ1(๐‘ฅ) =4720792684282308505367359๐‘ฅ2

2360410309588661890560000+

18553248327867926839๐‘ฅ3

1180205154794330945280000โˆ’ 2๐‘ฅ4 +

๐‘ฅ5 โˆ’3107407679๐‘ฅ8

218163673728000+

2887896659๐‘ฅ9

294520959532800+

7018307521๐‘ฅ10

1472604797664000โˆ’

22553๐‘ฅ11

4281076800+

4019๐‘ฅ12

3210807600โˆ’

718561๐‘ฅ14

1818030614400โˆ’

4019๐‘ฅ15

3718698984000+

1799641๐‘ฅ16

4958265312000โˆ’

10117717๐‘ฅ17

85587287385600โˆ’

68671๐‘ฅ18

655004750400+

127713533๐‘ฅ19

1941434080185600+

11676571๐‘ฅ20

7550021422944000โˆ’

2086087๐‘ฅ21

186529941037440+

11827๐‘ฅ22

3321402084000โˆ’

19๐‘ฅ23

49945896000+

๐‘ฅ24

61856071200โˆ’

๐‘ฅ25

111891780000โˆ’

1153๐‘ฅ26

672022030680000+

289๐‘ฅ27

112699346760000โˆ’

2857๐‘ฅ28

5522267991240000โˆ’

191๐‘ฅ30

1525197826152000โˆ’

๐‘ฅ31

38914512436800+

๐‘ฅ32

498105759191040.

The next iteration is

๐ฟ(๐‘ฃ2(๐‘ฅ)) + ๐‘(๐‘ฃ1(๐‘ฅ)) + ๐‘“(๐‘ฅ) = 0,

with boundary conditions ๐‘ฃ2(0) = ๐‘ฃ2โ€ฒ(0) = 0, ๐‘ฃ2(1) = ๐‘ฃ2โ€ฒ(1) = 1. (2.19)

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

48

By solving Eq. (2.19), we get

๐‘ฃ2(๐‘ฅ) = 1.9999999795270846๐‘ฅ2 + 2.745035293882598 ร— 10โˆ’8๐‘ฅ3 โˆ’

2๐‘ฅ4 + ๐‘ฅ5 โˆ’ 2.817792217763172 ร— 10โˆ’8๐‘ฅ8 +

2.079400216725163 ร— 10โˆ’8๐‘ฅ9 + 9.392717549543088 ร—

10โˆ’9๐‘ฅ10 + ๐‘‚[๐‘ฅ]11. (2.20)

In order to check the accuracy of the approximate solution, we calculate

the absolute error, where ๐‘ฃ(๐‘ฅ) = ๐‘ฅ5 โˆ’ 2๐‘ฅ4 + 2๐‘ฅ2 is the exact solution and

๐‘ฃ๐‘›(๐‘ฅ) is the approximate solution. In table 2.2 the absolute error of TAM with

n = 1, 2 is presented.

Table 2.2: Results of the absolute errors for TAM.

๐’™ |๐’“๐Ÿ| for TAM |๐’“๐Ÿ| for TAM

0 0 0

0.1 1.02627 ร— 10โˆ’7 1.77279 ร— 10โˆ’10

0.2 3.47659 ร— 10โˆ’7 5.99375 ร— 10โˆ’10

0.3 6.41401 ร— 10โˆ’7 1.1028 ร— 10โˆ’9

0.4 8.93924 ร— 10โˆ’7 1.53129 ร— 10โˆ’9

0.5 1.02777 ร— 10โˆ’6 1.752 ร— 10โˆ’9

0.6 9.93141 ร— 10โˆ’7 1.68284 ร— 10โˆ’9

0.7 7.86445 ร— 10โˆ’7 1.32351 ร— 10โˆ’9

0.8 4.64662 ร— 10โˆ’7 7.76486 ร— 10โˆ’10

0.9 1.471 ร— 10โˆ’7 2.44241 ร— 10โˆ’10

1.0 2.22045 ร— 10โˆ’16 1.11022 ร— 10โˆ’16

It can be seen clearly from table 2.2, that by increasing the iterations, the

errors will decreasing.

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

49

In order to discuss the convergence for TAM, suppose that ๐‘‡: [0,1] โ†’ ๐‘…, then

๐‘ฃ๐‘› = ๐‘‡(๐‘ฃ๐‘›โˆ’1) and 0 โ‰ค ๐‘ฅ โ‰ค 1.

The convergence issue can be done as follows:

Since, the exact solution is ๐‘ฃ = ๐‘ฃ(๐‘ฅ) = ๐‘ฅ5 โˆ’ 2๐‘ฅ4 + 2๐‘ฅ2, therefore, we have

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฃ0 โˆ’ (๐‘ฅ5 โˆ’ 2๐‘ฅ4 + 2๐‘ฅ2)โ€–,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฃ1 โˆ’ (๐‘ฅ5 โˆ’ 2๐‘ฅ4 + 2๐‘ฅ2)โ€– โ‰ค ๐‘˜โ€–๐‘ฃ0 โˆ’ (๐‘ฅ5 โˆ’ 2๐‘ฅ4 + 2๐‘ฅ2)โ€–

= ๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

But, โˆ€ ๐‘ฅ ๐œ– [0,1], 0 < ๐‘˜ < 1, when ๐‘ฅ = 1

3,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.99894 < 1,

Then, we have

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜ โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฃ2 โˆ’ (๐‘ฅ5 โˆ’ 2๐‘ฅ4 + 2๐‘ฅ2)โ€– โ‰ค ๐‘˜โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– =

๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Since, โˆ€ ๐‘ฅ ๐œ– [0,1], 0 < ๐‘˜ < 1, when ๐‘ฅ = 1

3,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 โ‡’ โˆš

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.99472 < 1,

Thus, we get

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Similarly, we have

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

50

โ€–๐‘ฃ3 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜3โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

By continuing in this way, we get

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘›โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Therefore,

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = 0 , and ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› = 0, then

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– =0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› = ๐‘ฃ = ๐‘ฅ5 โˆ’ 2๐‘ฅ4 + 2๐‘ฅ2, which is the exact

solution [1].

2.4.4 Solving the nonlinear Burgersโ€™ equation by using TAM

This subsection produces an implementation for the TAM to solve the

first order nonlinear Burgersโ€™ equation and finding the exact solutions for

different types of Burgersโ€™ equations in 1D, 2D and (1+3)-D.

Example 2.5:

Resolve example 1.5 by using TAM [33].

๐‘ฃ๐‘ก + ๐‘ฃ๐‘ฃ๐‘ฅ = ๐‘ฃ๐‘ฅ๐‘ฅ, with initial condition ๐‘ฃ(๐‘ฅ, 0) = 2๐‘ฅ. (2.21)

By applying TAM for Eq. (2.21), we get

๐ฟ(๐‘ฃ) = ๐‘ฃ๐‘ก , ๐‘(๐‘ฃ) = ๐‘ฃ๐‘ฃ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฅ๐‘ฅ and ๐‘“(๐‘ฅ, ๐‘ก) = 0.

Thus, the initial problem which needs to be solved is

๐ฟ(๐‘ฃ0(๐‘ฅ, ๐‘ก)) = 0, ๐‘ฃ0(๐‘ฅ, 0) = 2๐‘ฅ. (2.22)

By using a simple manipulation, one can solve Eq. (2.22) as follows:

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

51

โˆซ ๐‘ฃ0๐‘ก(๐‘ฅ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= 0, ๐‘ฃ0(๐‘ฅ, 0) = 2๐‘ฅ.

Then, we get

๐‘ฃ0(๐‘ฅ, ๐‘ก) = 2๐‘ฅ.

The second iteration can be carried through and is given as

๐ฟ(๐‘ฃ1(๐‘ฅ, ๐‘ก)) + ๐‘(๐‘ฃ0(๐‘ฅ, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ก) = 0, ๐‘ฃ1(๐‘ฅ, 0) = 2๐‘ฅ. (2.23)

By integrating both sides of Eq. (2.23) from 0 to t, we get

โˆซ ๐‘ฃ1๐‘ก(๐‘ฅ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ (โˆ’๐‘ฃ0(๐‘ฅ, ๐‘ก)๐‘ฃ0๐‘ฅ(๐‘ฅ, ๐‘ก) + ๐‘ฃ0๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ก)) โ…†๐‘ก๐‘ก

0

, ๐‘ฃ1(๐‘ฅ, 0) = 2๐‘ฅ.

Thus,

๐‘ฃ1(๐‘ฅ) = 2๐‘ฅ โˆ’ 4๐‘ฅ๐‘ก.

The next iteration is

๐ฟ(๐‘ฃ2(๐‘ฅ, ๐‘ก)) + ๐‘(๐‘ฃ1(๐‘ฅ, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ก) = 0, ๐‘ฃ2(๐‘ฅ, 0) = 2๐‘ฅ.

Then, we have

๐‘ฃ2(๐‘ฅ) = 2๐‘ฅ โˆ’ 4๐‘ฅ๐‘ก + 8๐‘ฅ๐‘ก2 โˆ’16๐‘ฅ๐‘ก3

3.

The next iteration is

๐ฟ(๐‘ฃ3(๐‘ฅ, ๐‘ก)) + ๐‘(๐‘ฃ2(๐‘ฅ, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ก) = 0, ๐‘ฃ3(๐‘ฅ, 0) = 2๐‘ฅ.

Then, we get

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

52

๐‘ฃ3(๐‘ฅ, ๐‘ก) = 2๐‘ฅ โˆ’ 4๐‘ฅ๐‘ก + 8๐‘ฅ๐‘ก2 โˆ’ 16๐‘ฅ๐‘ก3 +64๐‘ฅ๐‘ก4

3โˆ’

64๐‘ฅ๐‘ก5

3+

128๐‘ฅ๐‘ก6

9

โˆ’256๐‘ฅ๐‘ก7

63.

By continuing in this way, we will get series of the form:

๐‘ฃ(๐‘ฅ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ก) = 2๐‘ฅ โˆ’ 4๐‘ฅ๐‘ก + 8๐‘ฅ๐‘ก2 โˆ’ 16๐‘ฅ๐‘ก3 + 32๐‘ฅ๐‘ก4 โˆ’ โ‹ฏ,

This series converges to the exact solution [33]:

๐‘ฃ(๐‘ฅ, ๐‘ก) =2๐‘ฅ

1 + 2๐‘ก= 2๐‘ฅ โˆ’ 4๐‘ฅ๐‘ก + 8๐‘ฅ๐‘ก2 โˆ’ 16๐‘ฅ๐‘ก3 + 32๐‘ฅ๐‘ก4 โˆ’ 64๐‘ฅ๐‘ก5 + โ‹ฏ.

To check the convergence of the proposed method, let us suppose that T: ๐‘… ร—

[0,1

2) โ†’ ๐‘…2, then ๐‘ฃ๐‘› = ๐‘‡(๐‘ฃ๐‘›โˆ’1) and ๐‘ก โ‰ค

๐‘˜

2 , 0 < ๐‘˜ < 1.

According to the theorem 2.1 for nonlinear mapping T, a sufficient

condition for convergence of the TAM is strictly contraction T, the exact

solution is ๐‘ฃ = ๐‘ฃ(๐‘ฅ, ๐‘ก) =2๐‘ฅ

1+2๐‘ก, therefore, we have

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = โ€–2๐‘ฅ โˆ’2๐‘ฅ

1 + 2๐‘กโ€–,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– = โ€–2๐‘ฅ โˆ’ 4๐‘ฅ๐‘ก โˆ’2๐‘ฅ

1 + 2๐‘กโ€– โ‰ค ๐‘˜ โ€–2๐‘ฅ โˆ’

2๐‘ฅ

1 + 2๐‘กโ€– = ๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,,

But, โˆ€ ๐‘ก ๐œ– [0,๐‘˜

2) , 0 < ๐‘˜ < 1, when ๐‘ก =

1

4, ๐‘ฅ = 1,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.5 < 1,

Then, we get

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โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜ โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Also,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– = โ€–2๐‘ฅ โˆ’ 4๐‘ฅ๐‘ก + 8๐‘ฅ๐‘ก2 โˆ’16๐‘ฅ๐‘ก3

3โˆ’

2๐‘ฅ

1+2๐‘กโ€– โ‰ค ๐‘˜โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค

๐‘˜๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Since, โˆ€ ๐‘ก ๐œ– [0,๐‘˜

2) , 0 < ๐‘˜ < 1, when ๐‘ก =

1

4, ๐‘ฅ = 1,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 โ‡’ โˆš

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.353553 < 1,

Then, we have

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Similarly, we have

โ€–๐‘ฃ3 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜3โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

By continuing in this way, we get

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘›โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Therefore,

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = 0 , and ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› = 0, then

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– = 0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› = ๐‘ฃ =2๐‘ฅ

1+2๐‘ก , which is the exact solution [33].

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Example 2.6:

Let us recall example 1.6

๐‘ฃ๐‘ก + ๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ = ๐‘˜(๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ), (2.24)

with initial condition ๐‘ฃ(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ).

Applying the TAM by first distributing the equation as

๐ฟ(๐‘ฃ) = ๐‘ฃ๐‘ก , ๐‘(๐‘ฃ) = ๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ โˆ’ ๐‘˜(๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ) and ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0.

Thus, the initial problem which needs to be solved is

๐ฟ(๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)) = 0, ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ). (2.25)

By using simple manipulation, one can solve Eq. (2.25) as follows:

โˆซ ๐‘ฃ0๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= 0, ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ),

hence, we get

๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ).

The second iteration can be carried through and given as

๐ฟ(๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘(๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0,

with initial condition ๐‘ฃ1(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ). (2.26)

By integrating both sides of Eq. (2.26) from 0 to t, we get

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Chapter Two Semi-Analytical Iterative Method for Solving

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55

โˆซ ๐‘ฃ1๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ (โˆ’๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฃ0๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) โˆ’ ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฃ0๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ก

0

+ ๐‘˜(๐‘ฃ0๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) + ๐‘ฃ0๐‘ฆ๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ก))) โ…†๐‘ก,

with initial condition ๐‘ฃ1(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ). (2.27)

Thus,

๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’1

2๐œ‹๐‘ก๐‘ ๐‘–๐‘›(4๐œ‹๐‘ฅ) +

1

2๐œ‹๐‘ก๐‘ ๐‘–๐‘›(4๐œ‹๐‘ฆ) โˆ’

4๐œ‹2๐‘ก๐‘˜๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ โˆ’ 2๐œ‹๐‘ฆ) โˆ’ 4๐œ‹2๐‘ก๐‘˜๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ + 2๐œ‹๐‘ฆ) โˆ’

1

2๐œ‹๐‘ก๐‘ ๐‘–๐‘›(4๐œ‹๐‘ฅ + 4๐œ‹๐‘ฆ).

The next iteration is

๐ฟ(๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘(๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0,

with initial condition ๐‘ฃ2(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ). (2.28)

Then, we have

๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)

+1

2(โˆ’๐œ‹๐‘ ๐‘–๐‘›(4๐œ‹๐‘ฅ) + ๐œ‹๐‘ ๐‘–๐‘›(4๐œ‹๐‘ฆ) โˆ’ 8๐œ‹2๐‘˜๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ โˆ’ 2๐œ‹๐‘ฆ)

โˆ’ 8๐œ‹2๐‘˜๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ + 2๐œ‹๐‘ฆ) โˆ’ ๐œ‹๐‘ ๐‘–๐‘›(4๐œ‹๐‘ฅ + 4๐œ‹๐‘ฆ))๐‘ก + โ‹ฏ.

By continuing in this process till n = 4, we can get

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Chapter Two Semi-Analytical Iterative Method for Solving

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๐‘ฃ4(๐‘ฅ, ๐‘ฆ, ๐‘ก)

= ๐‘๐‘œ๐‘  (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘› (2๐œ‹๐‘ฅ) +1

2(โˆ’๐œ‹๐‘ ๐‘–๐‘› (4๐œ‹๐‘ฅ) + ๐œ‹๐‘ ๐‘–๐‘› (4๐œ‹๐‘ฆ)

โˆ’ 8๐œ‹2๐‘˜๐‘ ๐‘–๐‘› (2๐œ‹๐‘ฅ โˆ’ 2๐œ‹๐‘ฆ) โˆ’ 8๐œ‹2๐‘˜๐‘ ๐‘–๐‘› (2๐œ‹๐‘ฅ + 2๐œ‹๐‘ฆ) โˆ’ ๐œ‹๐‘ ๐‘–๐‘› (4๐œ‹๐‘ฅ

+ 4๐œ‹๐‘ฆ))๐‘ก + โ‹ฏ. (2.29)

Table 2.3 and Figure 2.2 illustrate the convergence of the solution

through the use of the maximal error remainder. Clearly seen, the errors will

be decreased as the number of iterations will be increased.

๐‘€๐ธ๐‘…๐‘› = ๐‘š๐‘Ž๐‘ฅ0โ‰ค๐‘ฅโ‰ค10โ‰ค๐‘ฆโ‰ค1

|๐ธ๐‘…๐‘›(๐‘ฅ, ๐‘ฆ)| , ๐‘› = 1, โ€ฆ , ๐‘š, when ๐‘˜ = 0.1, t =0.0001.

Table 2.3: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the TAM, where ๐‘› =1, โ€ฆ ,4.

n ๐‘ด๐‘ฌ๐‘น๐’ by TAM

1 5.99981 ร— 10โˆ’3

2 2.89069 ร— 10โˆ’6

3 1.12531 ร— 10โˆ’8

4 4.54397 ร— 10โˆ’11

Figure 2.2: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 4 by TAM.

1.0 1.5 2.0 2.5 3.0 3.5 4.0

10 10

10 8

10 6

10 4

10 2

n

ME

Rn

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Chapter Two Semi-Analytical Iterative Method for Solving

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Example 2.7 [76]:

Let us consider the following 2D Burgersโ€™ equation.

๐‘ฃ๐‘ก = ๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ , with initial condition ๐‘ฃ(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ. (2.30)

By using the TAM, we get the following:

๐ฟ(๐‘ฃ) = ๐‘ฃ๐‘ก , ๐‘(๐‘ฃ) = โˆ’๐‘ฃ๐‘ฃ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฅ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฆ๐‘ฆ and ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0.

Thus, the initial problem which needs to be solved is

๐ฟ(๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)) = 0, ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ. (2.31)

By using a simple manipulation, one can solve Eq. (2.31) as follows:

โˆซ ๐‘ฃ0๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= 0, ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ.

Then, we get

๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฅ + ๐‘ฆ.

The second iteration can be carried through and is given as

๐ฟ(๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘(๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0,

with initial condition ๐‘ฃ1(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ. (2.32)

By integrating both sides of Eq. (2.32) from 0 to t, we get

โˆซ ๐‘ฃ1๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ (๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฃ0๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) + ๐‘ฃ0๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) + ๐‘ฃ0๐‘ฆ๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ก)) โ…†๐‘ก๐‘ก

0

,

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Chapter Two Semi-Analytical Iterative Method for Solving

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with initial condition ๐‘ฃ1(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ.

Thus,

๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฅ + ๐‘ฆ + (๐‘ฅ + ๐‘ฆ)๐‘ก.

The next iteration is

๐ฟ(๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘(๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0, ๐‘ฃ2(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ.

Then, we have

๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ก) = (๐‘ฅ + ๐‘ฆ) + (๐‘ฅ + ๐‘ฆ)๐‘ก + (๐‘ฅ + ๐‘ฆ)๐‘ก2 +1

3(๐‘ฅ + ๐‘ฆ)๐‘ก3.

By continuing in this way, we will get series of the form:

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก) = (๐‘ฅ + ๐‘ฆ) + (๐‘ฅ + ๐‘ฆ)๐‘ก + (๐‘ฅ + ๐‘ฆ)๐‘ก2 +

(๐‘ฅ + ๐‘ฆ)๐‘ก3 + (๐‘ฅ + ๐‘ฆ)๐‘ก4 + โ‹ฏ.

This series converges to the exact solution [76]:

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) =๐‘ฅ + ๐‘ฆ

1 โˆ’ ๐‘ก,

= (๐‘ฅ + ๐‘ฆ) + (๐‘ฅ + ๐‘ฆ)๐‘ก + (๐‘ฅ + ๐‘ฆ)๐‘ก2 + (๐‘ฅ + ๐‘ฆ)๐‘ก3 + (๐‘ฅ + ๐‘ฆ)๐‘ก4

+ (๐‘ฅ + ๐‘ฆ)๐‘ก5 + โ‹ฏ.

In order to prove the convergence of TAM for 2D problem, let us assume that

T: ๐‘…2 ร— [0,1) โ†’ ๐‘…3, then ๐‘ฃ๐‘› = ๐‘‡(๐‘ฃ๐‘›โˆ’1), 0 โ‰ค ๐‘ก < 1.

By following similar steps as for example 2.5, since the exact solution is

๐‘ฃ = ๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) =๐‘ฅ+๐‘ฆ

1โˆ’๐‘ก, therefore, we have

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฅ + ๐‘ฆ โˆ’๐‘ฅ + ๐‘ฆ

1 โˆ’ ๐‘กโ€–,

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Chapter Two Semi-Analytical Iterative Method for Solving

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โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฅ + ๐‘ฆ + (๐‘ฅ + ๐‘ฆ)๐‘ก โˆ’๐‘ฅ + ๐‘ฆ

1 โˆ’ ๐‘กโ€– โ‰ค ๐‘˜ โ€–๐‘ฅ + ๐‘ฆ โˆ’

๐‘ฅ + ๐‘ฆ

1 โˆ’ ๐‘กโ€–

= ๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

But, โˆ€ ๐‘ก ๐œ– [0,1), when ๐‘ก = 1

2, ๐‘ฅ = 1, ๐‘ฆ = 1,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.5 < 1,

Then, we get

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜ โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Also,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– = โ€–(๐‘ฅ + ๐‘ฆ) + (๐‘ฅ + ๐‘ฆ)๐‘ก + (๐‘ฅ + ๐‘ฆ)๐‘ก2 +1

3(๐‘ฅ + ๐‘ฆ)๐‘ก3 โˆ’

๐‘ฅ + ๐‘ฆ

1 โˆ’ ๐‘กโ€–

โ‰ค ๐‘˜โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Since, โˆ€ ๐‘ก ๐œ– [0,1), when ๐‘ก = 1

2, ๐‘ฅ = 1, ๐‘ฆ = 1,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 โ‡’ โˆš

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.456435 < 1,

Thus,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Similarly, we have

โ€–๐‘ฃ3 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜3โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

By continuing in this way, we get:

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘›โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

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Therefore,

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = 0 , and ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› = 0, then

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– = 0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› = ๐‘ฃ =๐‘ฅ+๐‘ฆ

1โˆ’๐‘ก , which is the exact solution [76].

Example 2.8 [76]:

Let us consider, the following (1+3)-D Burgersโ€™ equation with the following

initial condition.

๐‘ฃ๐‘ก = ๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ + ๐‘ฃ๐‘ง๐‘ง,

with initial condition ๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง. (2.33)

Now, applying the proposed method by first distributing the equation as

๐ฟ(๐‘ฃ) = ๐‘ฃ๐‘ก , ๐‘(๐‘ฃ) = โˆ’๐‘ฃ๐‘ฃ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฅ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฆ๐‘ฆ โˆ’ ๐‘ฃ๐‘ง๐‘ง and ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 0.

Thus, the initial problem which needs to be solved is

๐ฟ(๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) = 0, ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง. (2.34)

By using a simple manipulation, one can solve Eq. (2.34) as follows:

โˆซ ๐‘ฃ0๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) โ…†๐‘ก๐‘ก

0

= 0, ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง.

Then, we get

๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘ฅ + ๐‘ฆ + ๐‘ง.

The second iteration can be carried through and is given as

๐ฟ(๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘(๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 0,

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with initial condition ๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง. (2.35)

By integrating both sides of Eq. (2.35) from 0 to t, we get

โˆซ ๐‘ฃ1๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ (๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)๐‘ฃ0๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) + ๐‘ฃ0๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)๐‘ก

0

+ ๐‘ฃ0๐‘ฆ๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) + ๐‘ฃ0๐‘ง๐‘ง(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) โ…†๐‘ก,

with initial condition ๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง.

Thus,

๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘ฅ + ๐‘ฆ + ๐‘ง + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก.

The next iteration is

๐ฟ(๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘(๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 0,

with initial condition ๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง.

Then, we have

๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= (๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2

+ 1

3(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3.

The next iteration is

๐ฟ(๐‘ฃ3(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘(๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 0,

with initial condition ๐‘ฃ3(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง.

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Then, we get

๐‘ฃ3(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= (๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2 + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3

+2

3(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก4 +

1

3(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก5.

By continuing in this way, we will get series of the form:

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก),

= (๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2 + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3

+ (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก4 + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก5 + โ‹ฏ,

This series converges to the exact solution [76]:

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) =๐‘ฅ + ๐‘ฆ + ๐‘ง

1 โˆ’ ๐‘ก,

= (๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2 + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3

+ (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก4 + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก5 + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก6 + โ‹ฏ.

For convergence issue, suppose that T: ๐‘…3 ร— [0,1) โ†’ ๐‘…4, then ๐‘ฃ๐‘› = ๐‘‡(๐‘ฃ๐‘›โˆ’1)

and 0 โ‰ค ๐‘ก < 1, similar procedure can be followed, the exact solution is

๐‘ฃ = ๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) =๐‘ฅ+๐‘ฆ+๐‘ง

1โˆ’๐‘ก, therefore, we have

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฅ + ๐‘ฆ + ๐‘ง โˆ’๐‘ฅ + ๐‘ฆ + ๐‘ง

1 โˆ’ ๐‘กโ€–,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฅ + ๐‘ฆ + ๐‘ง + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก โˆ’๐‘ฅ + ๐‘ฆ + ๐‘ง

1 โˆ’ ๐‘กโ€–

โ‰ค ๐‘˜ โ€–๐‘ฅ + ๐‘ฆ + ๐‘ง โˆ’๐‘ฅ + ๐‘ฆ + ๐‘ง

1 โˆ’ ๐‘กโ€– = ๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

But, โˆ€ ๐‘ก ๐œ– [0,1) , when ๐‘ก =1

3, ๐‘ฅ = 1, ๐‘ฆ = 1, ๐‘ง = 1,

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โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.333333 < 1,

Then, we get

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜ โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Moreover,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– = โ€–(๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2 +1

3(๐‘ฅ + ๐‘ฆ +

๐‘ง)๐‘ก3 โˆ’๐‘ฅ+๐‘ฆ+๐‘ง

1โˆ’๐‘กโ€– โ‰ค ๐‘˜โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘˜โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Since, โˆ€ ๐‘ก ๐œ– [0,1) , when ๐‘ก = 1

3, ๐‘ฅ = 1, ๐‘ฆ = 1, ๐‘ง = 1,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 โ‡’ โˆš

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜ = 0.293972 < 1,

Thus,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Similarly, we have

โ€–๐‘ฃ3 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜3โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

By continuing in this way, we get

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜๐‘›โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

Therefore,

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = 0 , and ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜๐‘› = 0, then

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๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– =0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› = ๐‘ฃ =๐‘ฅ+๐‘ฆ+๐‘ง

1โˆ’๐‘ก,which is the exact solution[76].

2.4.5 Solving the nonlinear system of Burgersโ€™ equations by the

TAM

Systems of partial differential equations have attracted much attention in

studying evolution equations describing wave propagation, in investigating

the shallow water waves [37, 48], examining the chemical reactionโ€“diffusion

model [48]. Moreover, systems of Burgersโ€™ equations have a lot of

importance in engineering and physical fields, engineering, chemistry, finance

and in different fields in science [5, 10, 36, 45, 61]. To solve many

researchers have been interested it by various techniques such as the lattice

Boltzmann method (LBM) [21], LADM [17], ADM [72] and the HAM [2]. In

this section, the TAM will be implemented to solve the Burgersโ€™ equation and

systems of Burgersโ€™ equations in 1D, 2D and 3D.

Example 2.9:

Let us consider, the following system of coupled Burgersโ€™ equation [50],

๐‘ข๐‘ก โˆ’ ๐‘ข๐‘ฅ๐‘ฅ โˆ’ 2๐‘ข๐‘ข๐‘ฅ + (๐‘ข๐‘ฃ)๐‘ฅ = 0,

๐‘ฃ๐‘ก โˆ’ ๐‘ฃ๐‘ฅ๐‘ฅ โˆ’ 2๐‘ฃ๐‘ฃ๐‘ฅ + (๐‘ข๐‘ฃ)๐‘ฅ = 0, ๐‘ฅ โˆˆ [โˆ’๐œ‹, ๐œ‹], ๐‘ก > 0,

Subject to the initial conditions:

๐‘ข(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ), ๐‘ฃ(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ). (2.36)

To solve the system of Eq. (2.36) by using the TAM, we have

๐ฟ1(๐‘ข) = ๐‘ข๐‘ก , ๐‘1(๐‘ข) = โˆ’๐‘ข๐‘ฅ๐‘ฅ โˆ’2๐‘ข๐‘ข๐‘ฅ + (๐‘ข๐‘ฃ)๐‘ฅ and ๐‘”(๐‘ฅ, ๐‘ก) = 0,

๐ฟ2(๐‘ฃ) = ๐‘ฃ๐‘ก , ๐‘2(๐‘ฃ) = โˆ’๐‘ฃ๐‘ฅ๐‘ฅ โˆ’2๐‘ฃ๐‘ฃ๐‘ฅ + (๐‘ข๐‘ฃ)๐‘ฅ and ๐‘“(๐‘ฅ, ๐‘ก) = 0.

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Thus, the initial problem which needs to be solved is

๐ฟ1(๐‘ข0(๐‘ฅ, ๐‘ก)) = 0, ๐‘ข0(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ),

๐ฟ2(๐‘ฃ0(๐‘ฅ, ๐‘ก)) = 0, ๐‘ฃ0(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ). (2.37)

By using simple manipulation, one can solve Eq. (2.37) as follows:

โˆซ ๐‘ข0๐‘ก(๐‘ฅ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= 0, ๐‘ข0(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ),

โˆซ ๐‘ฃ0๐‘ก(๐‘ฅ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= 0, ๐‘ฃ0(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ).

Therefore, we have

๐‘ข0(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ),

๐‘ฃ0(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ).

The second iteration can be carried through and is given as

๐ฟ1(๐‘ข1(๐‘ฅ, ๐‘ก)) + ๐‘1(๐‘ข0(๐‘ฅ, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ก) = 0, ๐‘ข1(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ),

๐ฟ2(๐‘ฃ1(๐‘ฅ, ๐‘ก)) + ๐‘2(๐‘ฃ0(๐‘ฅ, ๐‘ก)) + ๐‘”(๐‘ฅ, ๐‘ก) = 0, ๐‘ฃ1(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ). (2.38)

By integrating both sides of Eq. (2.38) from 0 to t, we get

โˆซ ๐‘ข1๐‘ก(๐‘ฅ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ [๐‘ข0๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ก) + 2๐‘ข0(๐‘ฅ, ๐‘ก)๐‘ข0๐‘ฅ(๐‘ฅ, ๐‘ก)๐‘ก

0

โˆ’ (๐‘ข0(๐‘ฅ, ๐‘ก)๐‘ฃ0(๐‘ฅ, ๐‘ก))๐‘ฅ

] โ…†๐‘ก , ๐‘ข1(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ),

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โˆซ ๐‘ฃ1๐‘ก(๐‘ฅ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ [๐‘ฃ0๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ก) + 2๐‘ฃ0(๐‘ฅ, ๐‘ก)๐‘ฃ0๐‘ฅ(๐‘ฅ, ๐‘ก)๐‘ก

0

โˆ’ (๐‘ข0(๐‘ฅ, ๐‘ก)๐‘ฃ0(๐‘ฅ, ๐‘ก))๐‘ฅ

] โ…†๐‘ก , ๐‘ฃ1(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ).

Thus, we get

๐‘ข1(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ),

๐‘ฃ1(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ).

The next iteration is

๐ฟ1(๐‘ข2(๐‘ฅ, ๐‘ก)) + ๐‘1(๐‘ข1(๐‘ฅ, ๐‘ก)) + ๐‘”(๐‘ฅ, ๐‘ก) = 0, ๐‘ข2(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ),

๐ฟ2(๐‘ฃ2(๐‘ฅ, ๐‘ก)) + ๐‘2(๐‘ฃ1(๐‘ฅ, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ก) = 0, ๐‘ฃ2(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ). (2.39)

Once again, by taking the integration to both sides of problem (2.39), we have

โˆซ ๐‘ข2๐‘ก(๐‘ฅ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ [๐‘ข1๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ก) + 2๐‘ข1(๐‘ฅ, ๐‘ก)๐‘ข1๐‘ฅ(๐‘ฅ, ๐‘ก)๐‘ก

0

โˆ’ (๐‘ข1(๐‘ฅ, ๐‘ก)๐‘ฃ1(๐‘ฅ, ๐‘ก))๐‘ฅ

] โ…†๐‘ก , ๐‘ข2(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ),

โˆซ ๐‘ฃ2๐‘ก(๐‘ฅ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ [๐‘ฃ1๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ก) + 2๐‘ฃ1(๐‘ฅ, ๐‘ก)๐‘ฃ1๐‘ฅ(๐‘ฅ, ๐‘ก)๐‘ก

0

โˆ’ (๐‘ข1(๐‘ฅ, ๐‘ก)๐‘ฃ1(๐‘ฅ, ๐‘ก))๐‘ฅ

] โ…†๐‘ก , ๐‘ฃ2(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ).

Therefore, we get

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๐‘ข2(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) +1

2๐‘ก2๐‘ ๐‘–๐‘›(๐‘ฅ),

๐‘ฃ2(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) +1

2๐‘ก2๐‘ ๐‘–๐‘›(๐‘ฅ).

By continuing in this way, we will get series of the form:

๐‘ข(๐‘ฅ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘›(๐‘ฅ, ๐‘ก),

= ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) +1

2๐‘ก2๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’

1

6๐‘ก3๐‘ ๐‘–๐‘›(๐‘ฅ) + โ‹ฏ,

๐‘ฃ(๐‘ฅ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ก),

= ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) +1

2๐‘ก2๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’

1

6๐‘ก3๐‘ ๐‘–๐‘›(๐‘ฅ) + โ‹ฏ.

This series converges to the exact solution [50],

๐‘ข(๐‘ฅ, ๐‘ก) = โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ),

๐‘ฃ(๐‘ฅ, ๐‘ก) = โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ).

The convergence, suppose that ๐‘ข๐‘› = ๐‘‡(๐‘ข๐‘›โˆ’1) and ๐‘ฃ๐‘› = ๐‘‡(๐‘ฃ๐‘›โˆ’1), 0 โ‰ค ๐‘ก < 1.

๐‘ข = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘›, ๐‘ฃ = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›.

Similar procedure can be followed, the exact solution is ๐‘ข = ๐‘ข(๐‘ฅ, ๐‘ก) =

โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ), and ๐‘ฃ = ๐‘ฃ(๐‘ฅ, ๐‘ก) = โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ), we have

โ€–๐‘ข0 โˆ’ ๐‘ขโ€– = โ€–๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ)โ€–,

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = โ€–๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ)โ€–.

Also,

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โ€–๐‘ข1 โˆ’ ๐‘ขโ€– = โ€–๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ)โ€– โ‰ค ๐‘˜1โ€–๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ)โ€–

= ๐‘˜1โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– = โ€–๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ)โ€– โ‰ค ๐‘˜2โ€–sin(๐‘ฅ) โˆ’ โ…‡โˆ’๐‘ก sin(๐‘ฅ)โ€–

= ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

But, โˆ€ ๐‘ก ๐œ– [0,1), when ๐‘ก = 1

4, ๐‘ฅ =

๐œ‹

2 ,

โ€–๐‘ข1 โˆ’ ๐‘ขโ€–

โ€–๐‘ข0 โˆ’ ๐‘ขโ€–โ‰ค ๐‘˜1 = 0.130203 < 1,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 = 0.130203 < 1.

Then, we get

โ€–๐‘ข1 โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜1โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

Also,

โ€–๐‘ข2 โˆ’ ๐‘ขโ€– = โ€–๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) +1

2๐‘ก2๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ)โ€– โ‰ค ๐‘˜1โ€–๐‘ข1 โˆ’

๐‘ขโ€– โ‰ค ๐‘˜1๐‘˜1โ€–๐‘ข0 โˆ’ ๐‘ขโ€– = ๐‘˜12โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– = โ€–๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) +1

2๐‘ก2๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ)โ€– โ‰ค ๐‘˜2โ€–๐‘ฃ1 โˆ’

๐‘ฃโ€– โ‰ค ๐‘˜2๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = ๐‘˜22โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

Since, โˆ€ ๐‘ก ๐œ– [0,1), when ๐‘ก = 1

4, ๐‘ฅ =

๐œ‹

2 ,

โ€–๐‘ข2 โˆ’ ๐‘ขโ€–

โ€–๐‘ข0 โˆ’ ๐‘ขโ€–โ‰ค ๐‘˜1

2 โ‡’ โˆšโ€–๐‘ข2 โˆ’ ๐‘ขโ€–

โ€–๐‘ข0 โˆ’ ๐‘ขโ€–โ‰ค ๐‘˜1 = 0.105226 < 1,

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โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2

2 โ‡’ โˆšโ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 = 0.105226 < 1.

Then, we have

โ€–๐‘ข2 โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜12โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜22โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

Similarly, we have

โ€–๐‘ข3 โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜13โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ3 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜23โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

By continuing in this way, we get:

โ€–๐‘ข๐‘› โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜1๐‘›โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2๐‘›โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

Therefore,

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ข๐‘› โˆ’ ๐‘ขโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜1๐‘› โ€–๐‘ข0 โˆ’ ๐‘ขโ€– = 0 , and ๐‘™๐‘–๐‘š

๐‘› โ†’ โˆž๐‘˜1

๐‘› = 0, then

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ข๐‘› โˆ’ ๐‘ขโ€– =0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘› = ๐‘ข = โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ), which is the exact

solution.

Similarly, we get

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜2๐‘› โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = 0 , and ๐‘™๐‘–๐‘š

๐‘› โ†’ โˆž๐‘˜2

๐‘› = 0, then

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๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– =0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› = ๐‘ฃ = โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ), which is the exact

solution [50].

Example 2.10 [30]:

Let us consider, the following system 2D Burgersโ€™ equation.

๐‘ข๐‘ก + ๐‘ข๐‘ข๐‘ฅ + ๐‘ฃ๐‘ข๐‘ฆ โˆ’ ๐‘ข๐‘ฅ๐‘ฅ โˆ’ ๐‘ข๐‘ฆ๐‘ฆ = 0,

๐‘ฃ๐‘ก + ๐‘ข๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ โˆ’ ๐‘ฃ๐‘ฅ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฆ๐‘ฆ = 0,

Subject to the initial conditions:

๐‘ข(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ, ๐‘ฃ(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ โˆ’ ๐‘ฆ. (2.40)

To solve the system of Eq. (2.40) by using the TAM

๐ฟ1(๐‘ข) = ๐‘ข๐‘ก , ๐‘1(๐‘ข) = ๐‘ข๐‘ข๐‘ฅ + ๐‘ฃ๐‘ข๐‘ฆ โˆ’ ๐‘ข๐‘ฅ๐‘ฅ โˆ’ ๐‘ข๐‘ฆ๐‘ฆ and ๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0,

๐ฟ2(๐‘ฃ) = ๐‘ฃ๐‘ก , ๐‘2(๐‘ฃ) = ๐‘ข๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ โˆ’ ๐‘ฃ๐‘ฅ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฆ๐‘ฆ and ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0.

Thus, the initial problem which needs to be solved is

๐ฟ1(๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ก)) = 0, ๐‘ข0(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ,

๐ฟ2(๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)) = 0, ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ โˆ’ ๐‘ฆ. (2.41)

By using a simple manipulation, one can solve Eq. (2.41) as follows:

โˆซ ๐‘ข0๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= 0, ๐‘ข0(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ,

โˆซ ๐‘ฃ0๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= 0, ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ โˆ’ ๐‘ฆ.

Then, we get

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๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ก) = (๐‘ฅ + ๐‘ฆ),

๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก) = (๐‘ฅ โˆ’ ๐‘ฆ).

The second iteration can be carried through and is given as

๐ฟ1(๐‘ข1(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘1(๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0, ๐‘ข1(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ,

๐ฟ2(๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘2(๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0, ๐‘ฃ1(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ โˆ’ ๐‘ฆ. (2.42)

By integrating both sides of Eq. (2.42) from 0 to t, we get

โˆซ ๐‘ข1๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ [โˆ’๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ข0๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) โˆ’ ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ข0๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ก

0

+ ๐‘ข0๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) + ๐‘ข0๐‘ฆ๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ก)] โ…†๐‘ก , ๐‘ข1(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ,

โˆซ ๐‘ฃ1๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ [โˆ’๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฃ0๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) โˆ’ ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฃ0๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ก

0

+ ๐‘ฃ0๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) + ๐‘ฃ0๐‘ฆ๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ก)] โ…†๐‘ก , ๐‘ฃ1(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ โˆ’ ๐‘ฆ.

Thus, we have

๐‘ข1(๐‘ฅ, ๐‘ฆ, ๐‘ก) = (๐‘ฅ + ๐‘ฆ) โˆ’ 2๐‘ก๐‘ฅ,

๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก) = (๐‘ฅ โˆ’ ๐‘ฆ) โˆ’ 2๐‘ก๐‘ฆ.

The next iteration is

๐ฟ1(๐‘ข2(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘1(๐‘ข1(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0,

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Chapter Two Semi-Analytical Iterative Method for Solving

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๐‘ข2(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ,

๐ฟ2(๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘2(๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = 0,

๐‘ฃ2(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ โˆ’ ๐‘ฆ. (2.43)

Once again, by taking the integration on both sides of problem (2.43), we

have

โˆซ ๐‘ข2๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ [โˆ’๐‘ข1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ข1๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) โˆ’ ๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ข1๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ก

0

+ ๐‘ข1๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) + ๐‘ข1๐‘ฆ๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ก)] โ…†๐‘ก , ๐‘ข2(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ,

โˆซ ๐‘ฃ2๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ [โˆ’๐‘ข1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฃ1๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) โˆ’ ๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฃ1๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ก

0

+ ๐‘ฃ1๐‘ฅ๐‘ฅ(๐‘ฅ, ๐‘ฆ, ๐‘ก) + ๐‘ฃ1๐‘ฆ๐‘ฆ(๐‘ฅ, ๐‘ฆ, ๐‘ก)] โ…†๐‘ก , ๐‘ฃ2(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ โˆ’ ๐‘ฆ.

Therefore, we get

๐‘ข2(๐‘ฅ, ๐‘ฆ, ๐‘ก) = (๐‘ฅ + ๐‘ฆ) โˆ’ 2๐‘ก๐‘ฅ + 2(๐‘ฅ + ๐‘ฆ)๐‘ก2 โˆ’4๐‘ก3๐‘ฅ

3,

๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ก) = (๐‘ฅ โˆ’ ๐‘ฆ) โˆ’ 2๐‘ก๐‘ฆ + (2๐‘ฅ โˆ’ 2๐‘ฆ)๐‘ก2 โˆ’4๐‘ก3๐‘ฆ

3.

By continuing in this way, we will get a series of the form:

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Chapter Two Semi-Analytical Iterative Method for Solving

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๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก) ,

= (๐‘ฅ + ๐‘ฆ) โˆ’ 2๐‘ฅ๐‘ก + 2(๐‘ฅ + ๐‘ฆ)๐‘ก2 โˆ’ 4๐‘ฅ๐‘ก3 + 4(๐‘ฅ + ๐‘ฆ)๐‘ก4 โˆ’ 8๐‘ฅ๐‘ก5

+ 8(๐‘ฅ + ๐‘ฆ)๐‘ก6 โˆ’ 16๐‘ฅ๐‘ก7 + 16(๐‘ฅ + ๐‘ฆ)๐‘ก8 โˆ’ โ‹ฏ,

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก),

= (๐‘ฅ โˆ’ ๐‘ฆ) โˆ’ 2๐‘ฆ๐‘ก + (2๐‘ฅ โˆ’ 2๐‘ฆ)๐‘ก2 โˆ’ 4๐‘ฆ๐‘ก3 + (4๐‘ฅ โˆ’ 4๐‘ฆ)๐‘ก4 โˆ’ 8๐‘ฆ๐‘ก5

+ (8๐‘ฅ โˆ’ 8๐‘ฆ)๐‘ก6 โˆ’ 16๐‘ฆ๐‘ก7 + (16๐‘ฅ โˆ’ 16๐‘ฆ)๐‘ก8 โˆ’ โ‹ฏ.

This series converges to the exact solution [30]:

๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ก) =๐‘ฅ โˆ’ 2๐‘ฅ๐‘ก + ๐‘ฆ

1 โˆ’ 2๐‘ก2,

= (๐‘ฅ + ๐‘ฆ) โˆ’ 2๐‘ฅ๐‘ก + 2(๐‘ฅ + ๐‘ฆ)๐‘ก2 โˆ’ 4๐‘ฅ๐‘ก3 + (4๐‘ฅ + 4๐‘ฆ)๐‘ก4 โˆ’ 8๐‘ฅ๐‘ก5

+ (8๐‘ฅ + 8๐‘ฆ)๐‘ก6 โˆ’ 16๐‘ฅ๐‘ก7 + (16๐‘ฅ + 16๐‘ฆ)๐‘ก8 โˆ’ 32๐‘ฅ๐‘ก9 + โ‹ฏ,

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) =๐‘ฅ โˆ’ 2๐‘ฆ๐‘ก โˆ’ ๐‘ฆ

1 โˆ’ 2๐‘ก2,

= (๐‘ฅ โˆ’ ๐‘ฆ) โˆ’ 2๐‘ฆ๐‘ก + (2๐‘ฅ โˆ’ 2๐‘ฆ)๐‘ก2 โˆ’ 4๐‘ฆ๐‘ก3 + (4๐‘ฅ โˆ’ 4๐‘ฆ)๐‘ก4 โˆ’ 8๐‘ฆ๐‘ก5

+ (8๐‘ฅ โˆ’ 8๐‘ฆ)๐‘ก6 โˆ’ 16๐‘ฆ๐‘ก7 + (16๐‘ฅ โˆ’ 16๐‘ฆ)๐‘ก8 โˆ’ 32๐‘ฆ๐‘ก9 + โ‹ฏ.

For convergence issue, suppose that ๐‘ข๐‘› = ๐‘‡(๐‘ข๐‘›โˆ’1), ๐‘ฃ๐‘› = ๐‘‡(๐‘ฃ๐‘›โˆ’1), 0 โ‰ค ๐‘ก < 1,

๐‘ข = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘›, ๐‘ฃ = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› .

Since, the exact solution is ๐‘ข = ๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ก) =๐‘ฅโˆ’2๐‘ฅ๐‘ก+๐‘ฆ

1โˆ’2๐‘ก2, and ๐‘ฃ = ๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) =

๐‘ฅโˆ’2๐‘ฆ๐‘กโˆ’๐‘ฆ

1โˆ’2๐‘ก2 , therefore, we have

โ€–๐‘ข0 โˆ’ ๐‘ขโ€– = โ€–๐‘ฅ + ๐‘ฆ โˆ’ (๐‘ฅ โˆ’ 2๐‘ฅ๐‘ก + ๐‘ฆ

1 โˆ’ 2๐‘ก2)โ€–,

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฅ โˆ’ ๐‘ฆ โˆ’ (๐‘ฅ โˆ’ 2๐‘ฆ๐‘ก โˆ’ ๐‘ฆ

1 โˆ’ 2๐‘ก2)โ€–.

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Also,

โ€–๐‘ข1 โˆ’ ๐‘ขโ€– = โ€–๐‘ฅ + ๐‘ฆ โˆ’ 2๐‘ก๐‘ฅ โˆ’ (๐‘ฅ โˆ’ 2๐‘ฅ๐‘ก + ๐‘ฆ

1 โˆ’ 2๐‘ก2)โ€–

โ‰ค ๐‘˜1 โ€–๐‘ฅ + ๐‘ฆ โˆ’ (๐‘ฅ โˆ’ 2๐‘ฅ๐‘ก + ๐‘ฆ

1 โˆ’ 2๐‘ก2)โ€– = ๐‘˜1โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฅ โˆ’ ๐‘ฆ โˆ’ 2๐‘ก๐‘ฆ โˆ’ (๐‘ฅโˆ’2๐‘ฆ๐‘กโˆ’๐‘ฆ

1โˆ’2๐‘ก2 )โ€– โ‰ค ๐‘˜2 โ€–๐‘ฅ โˆ’ ๐‘ฆ โˆ’ (๐‘ฅโˆ’2๐‘ฆ๐‘กโˆ’๐‘ฆ

1โˆ’2๐‘ก2)โ€– =

๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

But, โˆ€ ๐‘ก ๐œ– [0,1), when ๐‘ก = 1

4, ๐‘ฅ = 1, ๐‘ฆ = 1,

โ€–๐‘ข1 โˆ’ ๐‘ขโ€–

โ€–๐‘ข0 โˆ’ ๐‘ขโ€–โ‰ค ๐‘˜1 = 0.75 < 1,

and when ๐‘ก = 1

2, ๐‘ฅ = 0, ๐‘ฆ = 1,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 = 0.666667 < 1.

Then, we get

โ€–๐‘ข1 โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜1 โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2 โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

Also,

โ€–๐‘ข2 โˆ’ ๐‘ขโ€– = โ€–๐‘ฅ + ๐‘ฆ โˆ’ 2๐‘ก๐‘ฅ + 2(๐‘ฅ + ๐‘ฆ)๐‘ก2 โˆ’4๐‘ก3๐‘ฅ

3โˆ’ (

๐‘ฅโˆ’2๐‘ฅ๐‘ก+๐‘ฆ

1โˆ’2๐‘ก2 )โ€– โ‰ค

๐‘˜1โ€–๐‘ข1 โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜1๐‘˜1โ€–๐‘ข0 โˆ’ ๐‘ขโ€– = ๐‘˜12โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฅ โˆ’ ๐‘ฆ โˆ’ 2๐‘ก๐‘ฆ + (2๐‘ฅ โˆ’ 2๐‘ฆ)๐‘ก2 โˆ’4๐‘ก3๐‘ฆ

3โˆ’ (

๐‘ฅโˆ’2๐‘ฆ๐‘กโˆ’๐‘ฆ

1โˆ’2๐‘ก2 )โ€– โ‰ค

๐‘˜2โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = ๐‘˜22โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

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75

Since, โˆ€ ๐‘ก ๐œ– [0,1), when ๐‘ก = 1

4, ๐‘ฅ = 1, ๐‘ฆ = 1,

โ€–๐‘ข2 โˆ’ ๐‘ขโ€–

โ€–๐‘ข0 โˆ’ ๐‘ขโ€–โ‰ค ๐‘˜1

2 โ‡’ โˆšโ€–๐‘ข2 โˆ’ ๐‘ขโ€–

โ€–๐‘ข0 โˆ’ ๐‘ขโ€–โ‰ค ๐‘˜1 = 0.228218 < 1,

and when ๐‘ก = 1

2, ๐‘ฅ = 0, ๐‘ฆ = 1,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2

2 โ‡’ โˆšโ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 = 0.625485 < 1.

Thus,

โ€–๐‘ข2 โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜12โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜22โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

Similarly, we have

โ€–๐‘ข3 โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜13โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ3 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜23โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

By continuing in this way, we have

โ€–๐‘ข๐‘› โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜1๐‘›โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2๐‘›โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–.

Therefore,

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ข๐‘› โˆ’ ๐‘ขโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜1๐‘›โ€–๐‘ข0 โˆ’ ๐‘ขโ€– = 0 , and ๐‘™๐‘–๐‘š

๐‘› โ†’ โˆž๐‘˜1

๐‘› = 0, then

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ข๐‘› โˆ’ ๐‘ขโ€– =0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘› = ๐‘ข =๐‘ฅโˆ’2๐‘ฅ๐‘ก+๐‘ฆ

1โˆ’2๐‘ก2, which is the exact solution,

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Chapter Two Semi-Analytical Iterative Method for Solving

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Similarly, we have

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜2๐‘›โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = 0 , and ๐‘™๐‘–๐‘š

๐‘› โ†’ โˆž๐‘˜2

๐‘› = 0, then

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– = 0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› = ๐‘ฃ =๐‘ฅโˆ’2๐‘ฆ๐‘กโˆ’๐‘ฆ

1โˆ’2๐‘ก2 , which is the exact solution

[30].

Example 2.11:

Let us consider, the following system of 3D Burgersโ€™ equation,

๐‘ข๐‘ก โˆ’ ๐‘ข๐‘ข๐‘ฅ โˆ’ ๐‘ฃ๐‘ข๐‘ฆ โˆ’ ๐‘ค๐‘ข๐‘ง โˆ’ ๐‘ข๐‘ฅ๐‘ฅ โˆ’ ๐‘ข๐‘ฆ๐‘ฆ โˆ’ ๐‘ข๐‘ง๐‘ง = ๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก),

๐‘ฃ๐‘ก + ๐‘ข๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ + ๐‘ค๐‘ฃ๐‘ง + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ + ๐‘ฃ๐‘ง๐‘ง = ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก),

๐‘ค๐‘ก + ๐‘ข๐‘ค๐‘ฅ + ๐‘ฃ๐‘ค๐‘ฆ + ๐‘ค๐‘ค๐‘ง + ๐‘ค๐‘ฅ๐‘ฅ + ๐‘ค๐‘ฆ๐‘ฆ + ๐‘ค๐‘ง๐‘ง = โ„Ž(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก),

๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) โˆ’ โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)),

๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โˆ’โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) โˆ’ โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)),

โ„Ž(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) + โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)), (2.44)

Subject to the initial conditions:

๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง,

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = โˆ’(๐‘ฅ + ๐‘ฆ + ๐‘ง),

๐‘ค(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = 1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง.

To solve the system of Eq. (2.44) by using the TAM, we have

๐ฟ1(๐‘ข) = ๐‘ข๐‘ก , ๐‘1(๐‘ข) = โˆ’๐‘ข๐‘ข๐‘ฅ โˆ’ ๐‘ฃ๐‘ข๐‘ฆ โˆ’ ๐‘ค๐‘ข๐‘ง โˆ’ ๐‘ข๐‘ฅ๐‘ฅ โˆ’ ๐‘ข๐‘ฆ๐‘ฆ โˆ’ ๐‘ข๐‘ง๐‘ง,

โˆ’ ๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โˆ’โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) + โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)),

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๐ฟ2(๐‘ฃ) = ๐‘ฃ๐‘ก , ๐‘2(๐‘ฃ) = ๐‘ข๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ + ๐‘ค๐‘ฃ๐‘ง + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ + ๐‘ฃ๐‘ง๐‘ง,

โˆ’๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) + โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)),

๐ฟ3(๐‘ค) = ๐‘ค๐‘ก , ๐‘3(๐‘ค) = ๐‘ข๐‘ค๐‘ฅ + ๐‘ฃ๐‘ค๐‘ฆ + ๐‘ค๐‘ค๐‘ง + ๐‘ค๐‘ฅ๐‘ฅ + ๐‘ค๐‘ฆ๐‘ฆ + ๐‘ค๐‘ง๐‘ง,

โˆ’โ„Ž(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โˆ’โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) โˆ’ โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)).

Thus, the initial problem which needs to be solved is

๐ฟ1(๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) = โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) โˆ’ โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)),

๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง,

๐ฟ2(๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) = โˆ’โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) โˆ’ โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)),

๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = โˆ’(๐‘ฅ + ๐‘ฆ + ๐‘ง),

๐ฟ3(๐‘ค0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) = โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) + โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)),

๐‘ค0(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = 1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง. (2.45)

By using simple manipulation, one can solve Eq. (2.45) as follows:

โˆซ ๐‘ข0๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ [โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) โˆ’ โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง))] โ…†๐‘ก๐‘ก

0

,

๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง,

โˆซ ๐‘ฃ0๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ [โˆ’โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) โˆ’ โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง))] โ…†๐‘ก๐‘ก

0

,

๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = โˆ’(๐‘ฅ + ๐‘ฆ + ๐‘ง),

โˆซ ๐‘ค0๐‘ก(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) โ…†๐‘ก๐‘ก

0

= โˆซ [โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) + โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง))] โ…†๐‘ก๐‘ก

0

,

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๐‘ค0(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = 1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง.

Then, we get

๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= 1 โˆ’ โ…‡๐‘ก +๐‘ฅ

2+ โ…‡๐‘ก๐‘ฅ โˆ’

1

2โ…‡2๐‘ก๐‘ฅ +

๐‘ฆ

2+ โ…‡๐‘ก๐‘ฆ โˆ’

1

2โ…‡2๐‘ก๐‘ฆ +

๐‘ง

2+ โ…‡๐‘ก๐‘ง

โˆ’1

2โ…‡2๐‘ก๐‘ง,

๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= 1 โˆ’ โ…‡๐‘ก +๐‘ฅ

2โˆ’ โ…‡๐‘ก๐‘ฅ โˆ’

1

2โ…‡2๐‘ก๐‘ฅ +

๐‘ฆ

2โˆ’ โ…‡๐‘ก๐‘ฆ โˆ’

1

2โ…‡2๐‘ก๐‘ฆ +

๐‘ง

2โˆ’ โ…‡๐‘ก๐‘ง

โˆ’1

2โ…‡2๐‘ก๐‘ง,

๐‘ค0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= โ…‡๐‘ก โˆ’๐‘ฅ

2+ โ…‡๐‘ก๐‘ฅ +

1

2โ…‡2๐‘ก๐‘ฅ โˆ’

๐‘ฆ

2+ โ…‡๐‘ก๐‘ฆ +

1

2โ…‡2๐‘ก๐‘ฆ โˆ’

๐‘ง

2+ โ…‡๐‘ก๐‘ง

+1

2โ…‡2๐‘ก๐‘ง.

We turn the function ๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก), ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) and ๐‘ค0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) by using

Taylor series expansion to exponential function, we get

๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= (๐‘ฅ + ๐‘ฆ + ๐‘ง) โˆ’ ๐‘ก +1

2(โˆ’1 โˆ’ ๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก2 +

1

6(โˆ’1 โˆ’ 3๐‘ฅ โˆ’ 3๐‘ฆ

โˆ’ 3๐‘ง)๐‘ก3 +1

24(โˆ’1 โˆ’ 7๐‘ฅ โˆ’ 7๐‘ฆ โˆ’ 7๐‘ง)๐‘ก4 +

1

120(โˆ’1 โˆ’ 15๐‘ฅ โˆ’ 15๐‘ฆ

โˆ’ 15๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6,

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Some Ordinary and Partial Differential Equations

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๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง) + (โˆ’1 โˆ’ 2๐‘ฅ โˆ’ 2๐‘ฆ โˆ’ 2๐‘ง)๐‘ก +1

2(โˆ’1 โˆ’ 3๐‘ฅ โˆ’ 3๐‘ฆ

โˆ’ 3๐‘ง)๐‘ก2 +1

6(โˆ’1 โˆ’ 5๐‘ฅ โˆ’ 5๐‘ฆ โˆ’ 5๐‘ง)๐‘ก3 +

1

24(โˆ’1 โˆ’ 9๐‘ฅ โˆ’ 9๐‘ฆ

โˆ’ 9๐‘ง)๐‘ก4 +1

120(โˆ’1 โˆ’ 17๐‘ฅ โˆ’ 17๐‘ฆ โˆ’ 17๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6,

๐‘ค0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= (1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง) + (1 + 2๐‘ฅ + 2๐‘ฆ + 2๐‘ง)๐‘ก

+1

2(1 + 3๐‘ฅ + 3๐‘ฆ + 3๐‘ง)๐‘ก2 +

1

6(1 + 5๐‘ฅ + 5๐‘ฆ + 5๐‘ง)๐‘ก3

+1

24(1 + 9๐‘ฅ + 9๐‘ฆ + 9๐‘ง)๐‘ก4 +

1

120(1 + 17๐‘ฅ + 17๐‘ฆ + 17๐‘ง)๐‘ก5

+ ๐‘‚[๐‘ก]6.

The second iteration can be carried through and is given as

๐ฟ1(๐‘ข1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘1(๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 0,

๐‘ข1(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง,

๐ฟ2(๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘2(๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 0,

๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = โˆ’(๐‘ฅ + ๐‘ฆ + ๐‘ง),

๐ฟ3(๐‘ค1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘3(๐‘ค0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + โ„Ž(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 0,

๐‘ค1(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = 1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง. (2.46)

By integrating both sides of Eq. (2.46) from 0 to t, we turn the

function ๐‘ข1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก), ๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) and ๐‘ค1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) by using Taylor series

expansion to exponential function, we get

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Chapter Two Semi-Analytical Iterative Method for Solving

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๐‘ข1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= (๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(โˆ’2 โˆ’ ๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก2 +

1

6(โˆ’3

โˆ’ 5๐‘ฅ โˆ’ 5๐‘ฆ โˆ’ 5๐‘ง)๐‘ก3 +1

24(โˆ’2 โˆ’ 13๐‘ฅ โˆ’ 13๐‘ฆ โˆ’ 13๐‘ง)๐‘ก4 +

1

120(9

โˆ’ 23๐‘ฅ โˆ’ 23๐‘ฆ โˆ’ 23๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6,

๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง) + (โˆ’1 โˆ’ 2๐‘ฅ โˆ’ 2๐‘ฆ โˆ’ 2๐‘ง)๐‘ก +1

2(โˆ’1 โˆ’ 3๐‘ฅ โˆ’ 3๐‘ฆ

โˆ’ 3๐‘ง)๐‘ก2 +1

6(โˆ’1 โˆ’ 5๐‘ฅ โˆ’ 5๐‘ฆ โˆ’ 5๐‘ง)๐‘ก3 +

1

24(โˆ’1 โˆ’ 9๐‘ฅ โˆ’ 9๐‘ฆ

โˆ’ 9๐‘ง)๐‘ก4 +1

120(โˆ’1 โˆ’ 17๐‘ฅ โˆ’ 17๐‘ฆ โˆ’ 17๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6,

๐‘ค1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= (1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง) + (1 + 2๐‘ฅ + 2๐‘ฆ + 2๐‘ง)๐‘ก +1

2(1 + 3๐‘ฅ + 3๐‘ฆ

+ 3๐‘ง)๐‘ก2 +1

6(1 + 5๐‘ฅ + 5๐‘ฆ + 5๐‘ง)๐‘ก3 +

1

24(1 + 9๐‘ฅ + 9๐‘ฆ + 9๐‘ง)๐‘ก4

+1

120(1 + 17๐‘ฅ + 17๐‘ฆ + 17๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6.

The next iteration is

๐ฟ1(๐‘ข2(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘1(๐‘ข1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 0,

๐‘ข2(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง,

๐ฟ2(๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘2(๐‘ฃ1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 0,

๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = โˆ’(๐‘ฅ + ๐‘ฆ + ๐‘ง),

๐ฟ3(๐‘ค2(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + ๐‘3(๐‘ค1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)) + โ„Ž(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 0,

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๐‘ค2(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = 1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง.

Similarly, we have

๐‘ข2(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= (๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2 +

1

6(โˆ’4 โˆ’ 3๐‘ฅ

โˆ’ 3๐‘ฆ โˆ’ 3๐‘ง)๐‘ก3 +1

24(โˆ’15 โˆ’ 23๐‘ฅ โˆ’ 23๐‘ฆ โˆ’ 23๐‘ง)๐‘ก4 +

1

120(โˆ’16

โˆ’ 75๐‘ฅ โˆ’ 75๐‘ฆ โˆ’ 75๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6,

๐‘ฃ2(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง) + (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก +1

2(โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก2 +

1

6(โˆ’2

โˆ’ 3๐‘ฅ โˆ’ 3๐‘ฆ โˆ’ 3๐‘ง)๐‘ก3 +1

24(โˆ’7 โˆ’ 11๐‘ฅ โˆ’ 11๐‘ฆ โˆ’ 11๐‘ง)๐‘ก4

+1

120(โˆ’14 โˆ’ 31๐‘ฅ โˆ’ 31๐‘ฆ โˆ’ 31๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6,

๐‘ค2(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= (1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2 +

1

6(2

+ 3๐‘ฅ + 3๐‘ฆ + 3๐‘ง)๐‘ก3 +1

24(7 + 11๐‘ฅ + 11๐‘ฆ + 11๐‘ง)๐‘ก4 +

1

120(14

+ 31๐‘ฅ + 31๐‘ฆ + 31๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6.

By continuing in this way, we will get series of the form:

๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก),

= (๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2 +

1

6(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3 + โ‹ฏ,

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Some Ordinary and Partial Differential Equations

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๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) ,

= (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง) + (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก +1

2(โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก2

+1

6(โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก3 + โ‹ฏ,

๐‘ค(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ค๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) ,

= (1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2

+1

6(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3 + โ‹ฏ.

This series converges to the exact solution:

๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง),

= (๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2

+1

6(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3 +

1

24(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก4 + โ‹ฏ,

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โˆ’โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง),

= (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง) + (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก +1

2(โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก2

+1

6(โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก3 +

1

24(โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก4 + โ‹ฏ,

๐‘ค(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง),

= (1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2

+1

6(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3 +

1

24(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก4 + โ‹ฏ.

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Some Ordinary and Partial Differential Equations

83

Finally, the convergence can be done in the following steps, suppose that

๐‘ข๐‘› = ๐‘‡(๐‘ข๐‘›โˆ’1), ๐‘ฃ๐‘› = ๐‘‡(๐‘ฃ๐‘›โˆ’1) and ๐‘ค๐‘› = ๐‘‡(๐‘ค๐‘›โˆ’1), 0 โ‰ค ๐‘ก โ‰ค 1.

๐‘ข = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘› , ๐‘ฃ = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› , ๐‘ค = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ค๐‘› .

Since, the exact solution is

๐‘ข = ๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง),

๐‘ฃ = ๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โˆ’โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง),

๐‘ค = ๐‘ค(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง).

Therefore, we have

โ€–๐‘ข0 โˆ’ ๐‘ขโ€– = โ€–๐‘ข0 โˆ’ โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)โ€–,

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฃ0 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)โ€–,

โ€–๐‘ค0 โˆ’ ๐‘คโ€– = โ€–๐‘ค0 โˆ’ (1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง))โ€–.

Also,

โ€–๐‘ข1 โˆ’ ๐‘ขโ€– = โ€–๐‘ข1 โˆ’ โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)โ€– โ‰ค ๐‘˜1โ€–๐‘ข0 โˆ’ โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)โ€–

= ๐‘˜1โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฃ1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)โ€– โ‰ค ๐‘˜2โ€–๐‘ฃ0 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)โ€–

= ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

โ€–๐‘ค1 โˆ’ ๐‘คโ€– = โ€–๐‘ค1 โˆ’ (1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง))โ€–

โ‰ค ๐‘˜3โ€–๐‘ค0 โˆ’ (1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง))โ€– = ๐‘˜3โ€–๐‘ค0 โˆ’ ๐‘คโ€– .

But, โˆ€ ๐‘ก ๐œ– [0,1], when ๐‘ก = 1, ๐‘ฅ = 1, ๐‘ฆ = 1, ๐‘ง = 1,

โ€–๐‘ข1 โˆ’ ๐‘ขโ€–

โ€–๐‘ข0 โˆ’ ๐‘ขโ€–โ‰ค ๐‘˜1 = 0.82038 < 1,

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

84

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 = 0.673461 < 1,

โ€–๐‘ค1 โˆ’ ๐‘คโ€–

โ€–๐‘ค0 โˆ’ ๐‘คโ€–โ‰ค ๐‘˜3 = 0.673461 < 1.

Then, we get

โ€–๐‘ข1 โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜1โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

โ€–๐‘ค1 โˆ’ ๐‘คโ€– โ‰ค ๐‘˜3โ€–๐‘ค0 โˆ’ ๐‘คโ€–.

Also,

โ€–๐‘ข2 โˆ’ ๐‘ขโ€– = โ€–๐‘ข2 โˆ’ โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)โ€– โ‰ค ๐‘˜1โ€–๐‘ข1 โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜1๐‘˜1โ€–๐‘ข0 โˆ’ ๐‘ขโ€–

= ๐‘˜12โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– = โ€–๐‘ฃ2 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)โ€– โ‰ค ๐‘˜2โ€–๐‘ฃ1 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2๐‘˜2โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–

= ๐‘˜22โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

โ€–๐‘ค2 โˆ’ ๐‘คโ€– = โ€–๐‘ค2 โˆ’ (1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง))โ€– โ‰ค ๐‘˜3โ€–๐‘ค1 โˆ’ ๐‘คโ€– โ‰ค ๐‘˜3๐‘˜3โ€–๐‘ค0 โˆ’ ๐‘คโ€–

= ๐‘˜32โ€–๐‘ค0 โˆ’ ๐‘คโ€–.

Since, โˆ€ ๐‘ก ๐œ– [0,1], when ๐‘ก = 1, ๐‘ฅ = 1, ๐‘ฆ = 1, ๐‘ง = 1,

โ€–๐‘ข2 โˆ’ ๐‘ขโ€–

โ€–๐‘ข0 โˆ’ ๐‘ขโ€–โ‰ค ๐‘˜1

2 โ‡’ โˆšโ€–๐‘ข2 โˆ’ ๐‘ขโ€–

โ€–๐‘ข0 โˆ’ ๐‘ขโ€–โ‰ค ๐‘˜1 = 0.807042 < 1,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2

2 โ‡’ โˆšโ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€–

โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–โ‰ค ๐‘˜2 = 0.672965 < 1,

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

85

โ€–๐‘ค2 โˆ’ ๐‘คโ€–

โ€–๐‘ค0 โˆ’ ๐‘คโ€–โ‰ค ๐‘˜3

2 โ‡’ โˆšโ€–๐‘ค2 โˆ’ ๐‘คโ€–

โ€–๐‘ค0 โˆ’ ๐‘คโ€–โ‰ค ๐‘˜3 = 0.672965 < 1.

Then, we get

โ€–๐‘ข2 โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜12โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ2 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜22โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

โ€–๐‘ค2 โˆ’ ๐‘คโ€– โ‰ค ๐‘˜32โ€–๐‘ค0 โˆ’ ๐‘คโ€–.

Similarly, we have

โ€–๐‘ข3 โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜13โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ3 โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜23โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

โ€–๐‘ค3 โˆ’ ๐‘คโ€– โ‰ค ๐‘˜33โ€–๐‘ค0 โˆ’ ๐‘คโ€–.

By continuing in this way, we get:

โ€–๐‘ข๐‘› โˆ’ ๐‘ขโ€– โ‰ค ๐‘˜1๐‘›โ€–๐‘ข0 โˆ’ ๐‘ขโ€–,

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘˜2๐‘›โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€–,

โ€–๐‘ค๐‘› โˆ’ ๐‘คโ€– โ‰ค ๐‘˜3๐‘›โ€–๐‘ค0 โˆ’ ๐‘คโ€–.

Therefore,

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ข๐‘› โˆ’ ๐‘ขโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜1๐‘› โ€–๐‘ข0 โˆ’ ๐‘ขโ€– = 0 , and ๐‘™๐‘–๐‘š

๐‘› โ†’ โˆž๐‘˜1

๐‘› = 0, then

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ข๐‘› โˆ’ ๐‘ขโ€– =0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘› = ๐‘ข = โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง), which is the exact

solution,

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Chapter Two Semi-Analytical Iterative Method for Solving

Some Ordinary and Partial Differential Equations

86

Similarly, we have

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜2๐‘› โ€–๐‘ฃ0 โˆ’ ๐‘ฃโ€– = 0 , and ๐‘™๐‘–๐‘š

๐‘› โ†’ โˆž๐‘˜2

๐‘› = 0, then

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ฃ๐‘› โˆ’ ๐‘ฃโ€– =0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› = ๐‘ฃ = โˆ’โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง), which is the exact

solution,

Also,

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ค๐‘› โˆ’ ๐‘คโ€– โ‰ค ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘˜3๐‘› โ€–๐‘ค0 โˆ’ ๐‘คโ€– = 0 , and ๐‘™๐‘–๐‘š

๐‘› โ†’ โˆž๐‘˜3

๐‘› = 0, then

๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

โ€–๐‘ค๐‘› โˆ’ ๐‘คโ€– =0, then ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ค๐‘› = ๐‘ค = 1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง), which is the

exact solution.

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CHAPTER 3

BANACH CONTRACTION

METHOD FOR SOLVING SOME

ORDINARY AND PARTIAL

DIFFERENTIAL EQUATIONS

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Chapter Three Banach Contraction Method for Solving Some

Ordinary and Partial Differential Equations

87

Chapter 3

Banach Contraction Method for Solving Some

Ordinary and Partial Differential Equations

3.1 Introduction

Various analytic and semi-analytic iterative methods have been used to

solve many variant problems in different fields of the applied sciences have

significantly improved the iterative techniques. One of these methods is

Banach contraction method (BCM) based on using Banach contraction to

provide the required solution for different nonlinear kinds of functional

equations [75]. The BCM characterized as one of the developments of

Picardโ€™s method where the ease of application clearly observed which makes

it distinct from the other known iterative methods.

In this chapter, the BCM will be used to solve some important problems

in physics and engineering which already solved by TAM in chapter two. The

first part of this chapter will be presented the analytic solutions for Riccati,

pantograph, and beam deformation equations. Moreover, the BCM will be

used to solve 1D, 2D and 3D of Burgersโ€™ equations and systems of equations.

The BCM does not required any additional restrictions to deal with nonlinear

terms.

The work in this chapter is organized as follows: In section two, the

basic idea of the BCM will be presented. Section three discusses the

application of the BCM for the Riccati, pantograph, and beam deformation

equations. In section four, the BCM will be applied to solve Burgersโ€™

equations and system of equations in 1D, 2D and 3D.

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3.2 Contractions: Definition and Example

Definition 3.1: [3]

Let (๐‘‹, ๐‘‘) be a metric space. Then a mapping ๐‘“: ๐‘‹ โ†’ ๐‘‹,

(a) A point ๐‘ฅ โˆˆ ๐‘‹ is called a fixed point of ๐‘“ if ๐‘ฅ = ๐‘“(๐‘ฅ).

(b) ๐‘“ is called contraction if there exists a fixed constant ๐‘˜ < 1 such that

๐‘‘(๐‘“(๐‘ฅ), ๐‘“(๐‘ฆ)) โ‰ค ๐‘˜๐‘‘(๐‘ฅ, ๐‘ฆ), for all ๐‘ฅ, ๐‘ฆ in ๐‘‹.

A contraction mapping is also known as Banach contraction.

Example 3.1 [3]:

(a) Consider the usual metric space (๐‘…, ๐‘‘). Define

๐‘“(๐‘ฅ) =๐‘ฅ

๐‘Ž+ ๐‘, for all ๐‘ฅ โˆˆ ๐‘….

Then, ๐‘“ is contraction on ๐‘… if ๐‘Ž > 1 and the solution of the equation,

๐‘ฅ โˆ’ ๐‘“(๐‘ฅ) = 0 is ๐‘ฅ =๐‘Ž๐‘

๐‘Žโˆ’1.

(b) Consider the Euclidean metric space (๐‘…2, ๐‘‘). Define

๐‘“(๐‘ฅ, ๐‘ฆ) = (๐‘ฅ

๐‘Ž+ ๐‘,

๐‘ฆ

๐‘+ ๐‘), for all (๐‘ฅ, ๐‘ฆ) โˆˆ ๐‘…2.

Then, ๐‘“ is contraction on ๐‘…2 if ๐‘Ž, ๐‘ > 1. Now, solving the equation,

๐‘“(๐‘ฅ, ๐‘ฆ) = (๐‘ฅ, ๐‘ฆ) for a fixed point, we get is ๐‘ฅ =๐‘Ž๐‘

๐‘Žโˆ’1 and ๐‘ฆ =

๐‘๐‘

๐‘โˆ’1.

Using induction, one can easily get the following concerning iterates of a

contraction mapping.

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Chapter Three Banach Contraction Method for Solving Some

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If ๐‘“ is a contraction mapping on a metric space (๐‘‹, ๐‘‘) with contraction

constant ๐‘˜, then ๐‘“๐‘› (where the superscript represents the ๐‘›th iterate of ๐‘“) is

also a contraction on ๐‘‹ with constant ๐‘˜๐‘›.

3.3 Banach Contraction Principle

In 1922 Banach published his fixed point theorem also known as

Banachโ€™s Contraction Principle uses the concept of Lipschitz mapping. Also,

it has long been used in analysis to solve various kinds of differential and

integral equations [67].

Theorem 3.1 (Banach Contraction Principle): [75]

Let (๐‘‹, ๐‘‘) be a complete metric space and ๐‘“: ๐‘‹ โ†’ ๐‘‹ be a contraction

mapping. Then ๐‘“ has a unique fixed point ๐‘ฅ0 and for each ๐‘ฅ โˆˆ ๐‘‹, we have

๐‘™๐‘–๐‘š๐‘›โ†’โˆž

๐‘“๐‘›(๐‘ฅ) = ๐‘ฅ0,

Moreover for each ๐‘ฅ โˆˆ ๐‘‹, we have

๐‘‘(๐‘“๐‘›(๐‘ฅ), ๐‘ฅ0) โ‰ค ๐‘˜๐‘›

1 โˆ’ ๐‘˜๐‘‘(๐‘“(๐‘ฅ), ๐‘ฅ).

3.3.1 Solution of differential equations using Banach contraction

principle

Let ๐‘“(๐‘ฅ, ๐‘ฃ) be a continuous real-valued function on [๐‘Ž, ๐‘] ร— [๐‘, ๐‘‘]. The

Cauchy initial value problem is to find a continuous differentiable function

๐‘ฃ on [๐‘Ž, ๐‘] satisfying the differential equation [67],

๐‘ฃโ€ฒ(๐‘ฅ) = ๐‘“(๐‘ฅ, ๐‘ฃ(๐‘ฅ)), ๐‘ฃ(๐‘ฅ0) = ๐‘ฃ0 . (3.1)

Consider the Banach space ๐ถ[๐‘Ž, ๐‘] of continuous real-valued functions with

supremum norm defined by

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โ€–๐‘ฃโ€– = sup{ |๐‘ฃ(๐‘ฅ)| โˆถ ๐‘ฅ โˆˆ [๐‘Ž, ๐‘]}.

Integrate both sides of Eq. (3.1), we obtain an integral equation

๐‘ฃ(๐‘ฅ) = ๐‘ฃ0 + โˆซ ๐‘“(๐‘ก, ๐‘ฃ(๐‘ก)) ๐‘‘๐‘ก.๐‘ฅ

๐‘ฅ0

(3.2)

The problem (3.1) is equivalent the problem solving the integral equation

(3.2). We define an integral operator ๐น: ๐ถ[๐‘Ž, ๐‘] โ†’ ๐ถ[๐‘Ž, ๐‘] by

๐น๐‘ฃ(๐‘ฅ) = ๐‘ฃ0 + โˆซ ๐‘“(๐‘ก, ๐‘ฃ(๐‘ก)) ๐‘‘๐‘ก.๐‘ฅ

๐‘ฅ0

Thus, a solution of Cauchy initial value problem (3.1) corresponds with a

fixed point of ๐น. One may easily check that if ๐น is contraction, then the

problem (3.1) has a unique solution.

Now our purpose is to impose certain conditions on ๐‘“ under which the

integral operator ๐น is Lipschitz with ๐‘˜ < 1.

Theorem 3.2: [67]

Let ๐‘“(๐‘ฅ, ๐‘ฃ) be a continuous function of ๐ท๐‘œ๐‘š(๐‘“) = [๐‘Ž, ๐‘] ร— [๐‘, ๐‘‘] such

that ๐‘“ is Lipschitz with respect to ๐‘ฃ, that is there exists ๐‘˜ > 0 such that

|๐‘“(๐‘ฅ, ๐‘ฃ) โˆ’ ๐‘“(๐‘ฅ, ๐‘ข)| โ‰ค ๐‘˜|๐‘ฃ โˆ’ ๐‘ข|, for all ๐‘ฃ, ๐‘ข โˆˆ [๐‘, ๐‘‘] and for ๐‘ฅ โˆˆ [๐‘Ž, ๐‘].

Suppose (๐‘ฅ0, ๐‘ฃ0) โˆˆ ๐‘–๐‘›๐‘ก(๐ท๐‘œ๐‘š(๐‘“)). Then for sufficiently small โ„Ž > ๐‘œ, there

exists a unique solution of the problem (3.1).

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3.4 The basic idea of the BCM

Let us consider the general functional equation [75],

๐‘ฃ = ๐‘(๐‘ฃ) + ๐‘“ (3.3)

where ๐‘(๐‘ฃ) is a nonlinear operator and ๐‘“ is a known function.

Define successive approximations as

๐‘ฃ0 = ๐‘“,

๐‘ฃ1 = ๐‘ฃ0 + ๐‘(๐‘ฃ0),

๐‘ฃ2 = ๐‘ฃ0 + ๐‘(๐‘ฃ1),

๐‘ฃ3 = ๐‘ฃ0 + ๐‘(๐‘ฃ2),

โ‹ฎ

By continuing, we have

๐‘ฃ๐‘› = ๐‘ฃ0 + ๐‘(๐‘ฃ๐‘›โˆ’1), ๐‘› = 1,2,3, โ€ฆ . (3.4)

If ๐‘๐‘˜ is contraction for operator some positive integer k, then ๐‘(๐‘ฃ) has

a unique fixed-point and hence the sequence defined by Eq. (3.4) is

convergent in view of theorem 1.2, and the solution of Eq. (3.3) is given by

๐‘ฃ = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘› (3.5)

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3.5 The BCM to solve Riccati, pantograph and beam

deformation equations

In this section, three types of non-linear equations namely Riccati

equation, pantograph equation, and beam deformation equation will be solved

by the BCM.

3.5.1 Exact and numerical solutions for nonlinear Riccati

equation by BCM

The BCM will be implemented to solve the Riccati differential equation

which is a nonlinear ODE of first order, the following examples will be

solved.

Example 3.2:

Let us recall example 2.1:

๐‘ฃโ€ฒ = โ…‡๐‘ฅ โˆ’ โ…‡3๐‘ฅ + 2โ…‡2๐‘ฅ๐‘ฃ โˆ’ โ…‡๐‘ฅ๐‘ฃ2, with initial condition ๐‘ฃ(0) = 1. (3.6)

Eq. (3.6) can be converted to the following Voltera integral equation

๐‘ฃ(๐‘ฅ) = ๐‘“(๐‘ฅ) + ๐‘(๐‘ฃ), (3.7)

where

๐‘“(๐‘ฅ) =1

3+ โ…‡๐‘ฅ โˆ’

โ…‡3๐‘ฅ

3 and ๐‘(๐‘ฃ) = โˆซ (2โ…‡2๐‘ก๐‘ฃ โˆ’ โ…‡๐‘ก๐‘ฃ2) ๐‘‘๐‘ก.

๐‘ฅ

0

By implementing the BCM for Eq. (3.7), we have

๐‘ฃ๐‘›(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) + โˆซ (2โ…‡2๐‘ก๐‘ฃ๐‘›โˆ’1(๐‘ก) โˆ’ โ…‡๐‘ก๐‘ฃ๐‘›โˆ’12 (๐‘ก)) ๐‘‘๐‘ก,

๐‘ฅ

0

๐‘› = 1,2, โ€ฆ .

Then, we get

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Chapter Three Banach Contraction Method for Solving Some

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๐‘ฃ0(๐‘ฅ) = ๐‘“(๐‘ฅ) =1

3+ โ…‡๐‘ฅ โˆ’

โ…‡3๐‘ฅ

3,

๐‘ฃ1(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) + โˆซ (2โ…‡2๐‘ก๐‘ฃ0(๐‘ก) โˆ’ โ…‡๐‘ก๐‘ฃ02(๐‘ก)) ๐‘‘๐‘ก,

๐‘ฅ

0

=1

14+

8โ…‡๐‘ฅ

9+

โ…‡4๐‘ฅ

18โˆ’

โ…‡7๐‘ฅ

63,

The function ๐‘ฃ1(๐‘ฅ) can be written by using Taylor series expansion,

๐‘ฃ1(๐‘ฅ) = 1 + ๐‘ฅ +๐‘ฅ2

2โˆ’

๐‘ฅ3

6โˆ’

23๐‘ฅ4

24โˆ’

209๐‘ฅ5

120โˆ’

1639๐‘ฅ6

720โˆ’

12161๐‘ฅ7

5040

โˆ’87863๐‘ฅ8

40320โˆ’

625969๐‘ฅ9

362880โˆ’

4425479๐‘ฅ10

3628800+ ๐‘‚[๐‘ฅ]11,

๐‘ฃ2(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) + โˆซ (2โ…‡2๐‘ก๐‘ฃ1(๐‘ก) โˆ’ โ…‡๐‘ก๐‘ฃ12(๐‘ก)) ๐‘‘๐‘ก,

๐‘ฅ

0

= 11

9720+

195โ…‡๐‘ฅ

196+

โ…‡2๐‘ฅ

126โˆ’

โ…‡3๐‘ฅ

243โˆ’

โ…‡5๐‘ฅ

630+

โ…‡6๐‘ฅ

486+

โ…‡8๐‘ฅ

3528โˆ’

5โ…‡9๐‘ฅ

6804

+โ…‡12๐‘ฅ

6804โˆ’

โ…‡15๐‘ฅ

59535,

Similarly, by using Taylor series expansion, we have

๐‘ฃ2(๐‘ฅ) = 1 + ๐‘ฅ +๐‘ฅ2

2+

๐‘ฅ3

6+

๐‘ฅ4

24+

๐‘ฅ5

120+

๐‘ฅ6

720โˆ’

79๐‘ฅ7

5040โˆ’

3919๐‘ฅ8

40320

โˆ’116479๐‘ฅ9

362880โˆ’

2735039๐‘ฅ10

3628800+ ๐‘‚[๐‘ฅ]11,

Continuing in this way, we get a series of the form:

๐‘ฃ(๐‘ฅ) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ) = 1 + ๐‘ฅ +๐‘ฅ2

2+

๐‘ฅ3

6+

๐‘ฅ4

24+

๐‘ฅ5

120+ โ‹ฏ, (3.8)

This series converges to the following exact solution [19]:

๐‘ฃ(๐‘ฅ) = โ…‡๐‘ฅ.

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Example 3.3 [74]:

Rewrite the example 1.1 and solve it by BCM.

๐‘ฃโ€ฒ = โˆ’๐‘ฃ2 + 1, with initial condition ๐‘ฃ(0) = 0. (3.9)

Eq. (3.9) can be converted to the following Voltera integral equation

๐‘ฃ(๐‘ฅ) = ๐‘“(๐‘ฅ) + ๐‘(๐‘ฃ), (3.10)

where

๐‘“(๐‘ฅ) = ๐‘ฅ and ๐‘(๐‘ฃ) = โˆ’ โˆซ (๐‘ฃ2) ๐‘‘๐‘ก.๐‘ฅ

0

By applying the BCM for Eq. (3.10), we have

๐‘ฃ๐‘›(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) โˆ’ โˆซ (๐‘ฃ๐‘›โˆ’12 (๐‘ก)) ๐‘‘๐‘ก,

๐‘ฅ

0

๐‘› = 1,2, โ€ฆ .

Thus, we have

๐‘ฃ0(๐‘ฅ) = ๐‘“(๐‘ฅ) = ๐‘ฅ,

๐‘ฃ1(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) โˆ’ โˆซ(๐‘ฃ02(๐‘ก)) ๐‘‘๐‘ก = ๐‘ฅ โˆ’

๐‘ฅ3

3,

๐‘ฅ

0

๐‘ฃ2(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) โˆ’ โˆซ (๐‘ฃ12(๐‘ก)) ๐‘‘๐‘ก =

๐‘ฅ

0

๐‘ฅ โˆ’๐‘ฅ3

3+

2๐‘ฅ5

15โˆ’

๐‘ฅ7

63,

๐‘ฃ3(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) โˆ’ โˆซ (๐‘ฃ22(๐‘ก)) ๐‘‘๐‘ก,

๐‘ฅ

0

= ๐‘ฅ โˆ’๐‘ฅ3

3+

2๐‘ฅ5

15โˆ’

17๐‘ฅ7

315+

38๐‘ฅ9

2835โˆ’

134๐‘ฅ11

51975+

4๐‘ฅ13

12285โˆ’

๐‘ฅ15

59535,

By continuing in this manner till ๐‘› = 6, we have

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Chapter Three Banach Contraction Method for Solving Some

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๐‘ฃ6(๐‘ฅ) = ๐‘ฅ โˆ’๐‘ฅ3

3+

2๐‘ฅ5

15โˆ’

17๐‘ฅ7

315+

62๐‘ฅ9

2835โˆ’

1382๐‘ฅ11

155925+

21844๐‘ฅ13

6081075

โˆ’909409๐‘ฅ15

638512875+

543442๐‘ฅ17

986792625โˆ’

77145154๐‘ฅ19

371231385525+ โ‹ฏ, (3.11)

The obtained series solution in Eq. (3.9) can be used to calculate the

maximal error remainder for show the highest accuracy level that we can

achieve. This can be clearly seen in table 3.1 and figure 3.1

Table 3.1: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the BCM,

where ๐‘› = 1, โ€ฆ ,6.

n ๐‘ด๐‘ฌ๐‘น๐’ by BCM

1 6.65556 ร— 10โˆ’5

2 2.65463 ร— 10โˆ’7

3 7.56708 ร— 10โˆ’10

4 1.67808 ร— 10โˆ’12

5 3.04791 ร— 10โˆ’15

6 3.46945 ร— 10โˆ’18

Figure 3.1: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 6 by BCM.

1 2 3 4 5 6

10 15

10 11

10 7

n

ME

Rn

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3.5.2 BCM for solving linear pantograph equation

In this subsection, the BCM will be applied for second order linear

pantograph equation of order two. The following example presents a solution

for pantograph equation by using the BCM.

Example 3.4:

Resolve example 1.3 by using BCM [11].

๐‘ฃโ€ฒโ€ฒ =3

4๐‘ฃ + ๐‘ฃ (

๐‘ฅ

2) โˆ’ ๐‘ฅ2 + 2, (3.12)

with initial conditions ๐‘ฃ(0) = 0 , ๐‘ฃโ€ฒ(0) = 0.

Integrate both sides of Eq. (3.12) twice from 0 to ๐‘ฅ and using the initial

condition at ๐‘ฅ = 0, we get

๐‘ฃ(๐‘ฅ) = ๐‘ฅ2 โˆ’๐‘ฅ4

12+ โˆซ โˆซ (

3

4๐‘ฃ(๐‘ก) + ๐‘ฃ (

๐‘ก

2)) ๐‘‘๐‘ก๐‘‘๐‘ก,

๐‘ฅ

0

๐‘ฅ

0

(3.13)

By using the formula in Eq. (1.6), we get

๐‘ฃ(๐‘ฅ) = ๐‘ฅ2 โˆ’๐‘ฅ4

12+ โˆซ (๐‘ฅ โˆ’ ๐‘ก) (

3

4๐‘ฃ(๐‘ก) + ๐‘ฃ (

๐‘ก

2)) ๐‘‘๐‘ก

๐‘ฅ

0

, (3.14)

By applying the BCM for Eq. (3.14), we get

๐‘ฃ(๐‘ฅ) = ๐‘“(๐‘ฅ) + ๐‘(๐‘ฃ),

where

๐‘“(๐‘ฅ) = ๐‘ฅ2 โˆ’๐‘ฅ4

12 and ๐‘(๐‘ฃ) = โˆซ (๐‘ฅ โˆ’ ๐‘ก) (

3

4๐‘ฃ(๐‘ก) + ๐‘ฃ (

๐‘ก

2)) ๐‘‘๐‘ก

๐‘ฅ

0

,

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๐‘ฃ๐‘›(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) + โˆซ (๐‘ฅ โˆ’ ๐‘ก) (3

4๐‘ฃ๐‘›โˆ’1(๐‘ก) + ๐‘ฃ๐‘›โˆ’1 (

๐‘ก

2)) ๐‘‘๐‘ก,

๐‘ฅ

0

๐‘› = 1,2, โ€ฆ .

Thus, by applying the Mathematicaโ€™s code, see appendix D, we have

๐‘ฃ0(๐‘ฅ) = ๐‘“(๐‘ฅ) = ๐‘ฅ2 โˆ’๐‘ฅ4

12,

๐‘ฃ1(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) + โˆซ (๐‘ฅ โˆ’ ๐‘ก) (3

4๐‘ฃ0(๐‘ก) + ๐‘ฃ0 (

๐‘ก

2)) ๐‘‘๐‘ก =

๐‘ฅ

0

๐‘ฅ2 โˆ’13๐‘ฅ6

5760,

๐‘ฃ2(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) + โˆซ (๐‘ฅ โˆ’ ๐‘ก) (3

4๐‘ฃ1(๐‘ก) + ๐‘ฃ1 (

๐‘ก

2)) ๐‘‘๐‘ก

๐‘ฅ

0

= ๐‘ฅ2 โˆ’91๐‘ฅ8

2949120,

๐‘ฃ3(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ) + โˆซ (๐‘ฅ โˆ’ ๐‘ก) (3

4๐‘ฃ2(๐‘ก) + ๐‘ฃ2 (

๐‘ก

2)) ๐‘‘๐‘ก

๐‘ฅ

0

,

= ๐‘ฅ2 โˆ’17563๐‘ฅ10

67947724800,

By continuing in this way, we get

๐‘ฃ(๐‘ฅ) = ๐‘ฅ2 โˆ’ small term, (3.15)

This series converges to the exact solution [11]:

๐‘ฃ(๐‘ฅ) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ) = ๐‘ฅ2.

3.5.3 Solving the nonlinear beam equation by using BCM

In this subsection, the BCM will be implemented to solve fourth order

nonlinear beam deformation problem.

Example 3.5:

Resolve example 1.4 by using BCM [1].

๐‘ฃ(4) = ๐‘ฃ2 โˆ’ ๐‘ฅ10 + 4๐‘ฅ9 โˆ’ 4๐‘ฅ8 โˆ’ 4๐‘ฅ7 + 8๐‘ฅ6 โˆ’ 4๐‘ฅ4 + 120๐‘ฅ โˆ’ 48,

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with the boundary conditions ๐‘ฃ(0) = ๐‘ฃโ€ฒ(0) = 0, ๐‘ฃ(1) = ๐‘ฃโ€ฒ(1) = 1. (3.16)

By integrating both sides of Eq. (3.16) four times from 0 to ๐‘ฅ, we obtain

๐‘ฃ(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ)

+ โˆซ โˆซ โˆซ โˆซ (๐‘ฃ2 โˆ’ ๐‘ก10 + 4๐‘ก9 โˆ’ 4๐‘ก8 โˆ’ 4๐‘ก7 + 8๐‘ก6 โˆ’ 4๐‘ก4๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

๐‘ฅ

0

+ 120๐‘ก โˆ’ 48) ๐‘‘๐‘ก ๐‘‘๐‘ก ๐‘‘๐‘ก ๐‘‘๐‘ก . (3.17)

Let us assume the following initial component,

๐‘ฃ0(๐‘ฅ) = ๐‘Ž๐‘ฅ3 + ๐‘๐‘ฅ2 + ๐‘๐‘ฅ + ๐‘‘,

By using Eq. (1.6), we obtain the following

๐‘ฃ(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ)

+ โˆซ(๐‘ฅ โˆ’ ๐‘ก)3

6(๐‘ฃ2 โˆ’ ๐‘ก10 + 4๐‘ก9 โˆ’ 4๐‘ก8 โˆ’ 4๐‘ก7 + 8๐‘ก6 โˆ’ 4๐‘ก4

๐‘ฅ

0

+ 120๐‘ก โˆ’ 48) ๐‘‘๐‘ก, (3.18)

By implementing the BCM:

๐‘ฃ๐‘›(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ)

+ โˆซ(๐‘ฅ โˆ’ ๐‘ก)3

6(๐‘ฃ๐‘›โˆ’1

2 (๐‘ก) โˆ’ ๐‘ก10 + 4๐‘ก9 โˆ’ 4๐‘ก8 โˆ’ 4๐‘ก7 + 8๐‘ก6 โˆ’ 4๐‘ก4๐‘ฅ

0

+ 120๐‘ก โˆ’ 48) ๐‘‘๐‘ก, ๐‘› = 1,2,3, โ€ฆ. (3.19)

Then, we get

๐‘ฃ0(๐‘ฅ) = ๐‘“(๐‘ฅ) = ๐‘Ž๐‘ฅ3 + ๐‘๐‘ฅ2 + ๐‘๐‘ฅ + ๐‘‘,

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99

๐‘ฃ1(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ)

+ โˆซ(๐‘ฅ โˆ’ ๐‘ก)3

6(๐‘ฃ0

2(๐‘ก) โˆ’ ๐‘ก10 + 4๐‘ก9 โˆ’ 4๐‘ก8 โˆ’ 4๐‘ก7 + 8๐‘ก6 โˆ’ 4๐‘ก4๐‘ฅ

0

+ 120๐‘ก โˆ’ 48) ๐‘‘๐‘ก,

= ๐‘‘ + ๐‘๐‘ฅ + ๐‘๐‘ฅ2 + ๐‘Ž๐‘ฅ3 โˆ’ 2๐‘ฅ4 +๐‘‘2๐‘ฅ4

24+ ๐‘ฅ5 +

1

60๐‘๐‘‘๐‘ฅ5 +

๐‘2๐‘ฅ6

360

+1

180๐‘๐‘‘๐‘ฅ6 +

1

420๐‘๐‘๐‘ฅ7 +

1

420๐‘Ž๐‘‘๐‘ฅ7 โˆ’

๐‘ฅ8

420+

๐‘2๐‘ฅ8

1680

+1

840๐‘Ž๐‘๐‘ฅ8 +

๐‘Ž๐‘๐‘ฅ9

1512+

๐‘ฅ10

630+

๐‘Ž2๐‘ฅ10

5040โˆ’

๐‘ฅ11

1980โˆ’

๐‘ฅ12

2970+

๐‘ฅ13

4290

โˆ’๐‘ฅ14

24024, (3.20)

Imposing the boundary conditions (3.16), into ๐‘ฃ1(๐‘ฅ), we get

๐‘Ž = โˆ’0.00687154, ๐‘ = 2.00593, ๐‘ = 0, ๐‘‘ = 0. (3.21)

The following first-order approximate solution is achieved:

๐‘ฃ1(๐‘ฅ) = 2.005929514398968๐‘ฅ2 โˆ’ 6.871538792438514 ร— 10โˆ’3๐‘ฅ3

โˆ’ 2๐‘ฅ4 + ๐‘ฅ5 + 1.413881948623746 ร— 10โˆ’5๐‘ฅ8

โˆ’ 9.116284704424509 ร— 10โˆ’6๐‘ฅ9 + 1.587310955961384

ร— 10โˆ’3๐‘ฅ10 โˆ’๐‘ฅ11

1980โˆ’

๐‘ฅ12

2970+

๐‘ฅ13

4290โˆ’

๐‘ฅ14

24024. (3.22)

๐‘ฃ2(๐‘ฅ) = ๐‘ฃ0(๐‘ฅ)

+ โˆซ(๐‘ฅ โˆ’ ๐‘ก)3

6(๐‘ฃ1

2(๐‘ก) โˆ’ ๐‘ก10 + 4๐‘ก9 โˆ’ 4๐‘ก8 โˆ’ 4๐‘ก7 + 8๐‘ก6 โˆ’ 4๐‘ก4๐‘ฅ

0

+ 120๐‘ก โˆ’ 48) ๐‘‘๐‘ก,

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= ๐‘‘ + ๐‘๐‘ฅ + ๐‘๐‘ฅ2 + ๐‘Ž๐‘ฅ3 โˆ’ 2๐‘ฅ4 +๐‘‘2๐‘ฅ4

24+ ๐‘ฅ5 +

1

60๐‘๐‘‘๐‘ฅ5 +

๐‘2๐‘ฅ6

360

+1

180๐‘๐‘‘๐‘ฅ6 +

1

420๐‘๐‘๐‘ฅ7 +

1

420๐‘Ž๐‘‘๐‘ฅ7 โˆ’

๐‘ฅ8

420+

๐‘2๐‘ฅ8

1680

+1

840๐‘Ž๐‘๐‘ฅ8 โˆ’

๐‘‘๐‘ฅ8

420+

๐‘‘3๐‘ฅ8

20160+

๐‘Ž๐‘๐‘ฅ9

1512โˆ’

๐‘๐‘ฅ9

756+ โ‹ฏ. (3.23)

Once again, by imposing the boundary conditions (3.16) in the second

component ๐‘ฃ2(๐‘ฅ), the obtained coefficients will be:

๐‘Ž = โˆ’8.27907 ร— 10โˆ’7, ๐‘ = 2, ๐‘ = 0, ๐‘‘ = 0.

In order to check the accuracy of the approximate solution, we calculate

the absolute error, where ๐‘ฃ(๐‘ฅ) = ๐‘ฅ5 โˆ’ 2๐‘ฅ4 + 2๐‘ฅ2 is the exact solution and

๐‘ฃ๐‘›(๐‘ฅ) is the approximate solution. In table 3.2 the absolute error of BCM with

๐‘› = 1, 2. It can be seen clearly from table 3.2 by increasing the iteration, the

error will be decreasing.

Table 3.2: Results of the absolute errors for BCM.

x |๐’“๐Ÿ| for BCM |๐’“๐Ÿ| for BCM

0 0 0

0.1 5.24236 ร— 10โˆ’5 6.79965 ร— 10โˆ’9

0.2 1.82208 ร— 10โˆ’4 2.3887 ร— 10โˆ’8

0.3 3.48134 ร— 10โˆ’4 4.62946 ร— 10โˆ’8

0.4 5.09092 ร— 10โˆ’4 6.90558 ร— 10โˆ’8

0.5 6.24721ร— 10โˆ’4 8.72068 ร— 10โˆ’8

0.6 6.57823 ร— 10โˆ’4 9.58101 ร— 10โˆ’8

0.7 5.81138 ร— 10โˆ’4 9.01332 ร— 10โˆ’8

0.8 3.92709 ร— 10โˆ’4 6.67054 ร— 10โˆ’8

0.9 1.45715 ร— 10โˆ’4 2.80674 ร— 10โˆ’8

1.0 3.3447 ร— 10โˆ’8 0

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3.5.4 Solving the nonlinear Burgersโ€™ equation by using the BCM

In this subsection, we implement the BCM to solve the first order

nonlinear Burgersโ€™ equation and finding the exact solutions for different types

of Burgersโ€™ equations in 1D, 2D and (1+3)-D.

Example 3.6:

Rewrite the example 1.5 and solve it by BCM [33].

๐‘ฃ๐‘ก + ๐‘ฃ๐‘ฃ๐‘ฅ = ๐‘ฃ๐‘ฅ๐‘ฅ, with initial condition ๐‘ฃ(๐‘ฅ, 0) = 2๐‘ฅ. (3.24)

Integrating both sides of Eq. (3.24) from 0 to ๐‘ก and using the initial condition

at ๐‘ก = 0, we get

๐‘ฃ(๐‘ฅ, ๐‘ก) = 2๐‘ฅ + โˆซ (โˆ’๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฅ๐‘ฅ) ๐‘‘๐‘ก,๐‘ก

0

(3.25)

Applying the BCM for Eq. (3.25), we get

๐‘ฃ(๐‘ฅ, ๐‘ก) = ๐‘“(๐‘ฅ, ๐‘ก) + ๐‘(๐‘ฃ),

where

๐‘“(๐‘ฅ, ๐‘ก) = 2๐‘ฅ and ๐‘(๐‘ฃ) = โˆซ (โˆ’๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฅ๐‘ฅ) ๐‘‘๐‘ก.๐‘ก

0

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ก) = ๐‘ฃ0(๐‘ฅ, ๐‘ก) + โˆซ (โˆ’๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ก)(๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ก))๐‘ฅ

+ (๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ก))๐‘ฅ๐‘ฅ

) ๐‘‘๐‘ก,๐‘ก

0

๐‘› = 1,2, โ€ฆ. (3.26)

Then, we have

๐‘ฃ0 = ๐‘“(๐‘ฅ, ๐‘ก) = 2๐‘ฅ,

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๐‘ฃ1 = ๐‘ฃ0 + โˆซ (โˆ’๐‘ฃ0๐‘ฃ0๐‘ฅ + ๐‘ฃ0๐‘ฅ๐‘ฅ) ๐‘‘๐‘ก = ๐‘ก

0

2๐‘ฅ โˆ’ 4๐‘ก๐‘ฅ,

๐‘ฃ2 = ๐‘ฃ0 + โˆซ (โˆ’๐‘ฃ1๐‘ฃ1๐‘ฅ + ๐‘ฃ1๐‘ฅ๐‘ฅ) ๐‘‘๐‘ก = ๐‘ก

0

2๐‘ฅ โˆ’ 4๐‘ก๐‘ฅ + 8๐‘ก2๐‘ฅ โˆ’16๐‘ก3๐‘ฅ

3,

By continuing in this way, the result is

๐‘ฃ(๐‘ฅ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ก) ,

= 2x โˆ’ 4xt + 8xt2 โˆ’ 16xt3 + 32xt4 โˆ’ 64xt5 + โ‹ฏ, (3.27)

This series converges to the following exact solution [33]:

๐‘ฃ(๐‘ฅ, ๐‘ก) =2๐‘ฅ

1 + 2๐‘ก= 2๐‘ฅ โˆ’ 4๐‘ฅ๐‘ก + 8๐‘ฅ๐‘ก2 โˆ’ 16๐‘ฅ๐‘ก3 + 32๐‘ฅ๐‘ก4 โˆ’ 64๐‘ฅ๐‘ก5 + โ‹ฏ.

Example 3.7:

Recall example 1.6:

๐‘ฃ๐‘ก + ๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ = ๐‘˜(๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ), (3.28)

with initial condition ๐‘ฃ(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ).

By taking the integration on both sides of equation (3.28) from 0 to ๐‘ก, we

obtain

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)

+ โˆซ (โˆ’๐‘ฃ๐‘ฃ๐‘ฅโˆ’๐‘ฃ๐‘ฃ๐‘ฆ + ๐‘˜(๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ก,๐‘ก

0

(3.29)

Now, by applying the BCM for Eq. (3.29), we have

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) + ๐‘(๐‘ฃ),

where

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๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ) and

๐‘(๐‘ฃ) = โˆซ (โˆ’๐‘ฃ๐‘ฃ๐‘ฅโˆ’๐‘ฃ๐‘ฃ๐‘ฆ + ๐‘˜(๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ก.๐‘ก

0

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก)

= ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)

+ โˆซ (โˆ’๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฅ โˆ’ ๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฆ

๐‘ก

0

+ ๐‘˜(๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ก, ๐‘› = 1,2, โ€ฆ. (3.30)

So, we get

๐‘ฃ0 = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ),

๐‘ฃ1 = ๐‘ฃ0 + โˆซ (โˆ’๐‘ฃ0๐‘ฃ0๐‘ฅ โˆ’ ๐‘ฃ0๐‘ฃ0๐‘ฆ + ๐‘˜(๐‘ฃ0๐‘ฅ๐‘ฅ + ๐‘ฃ0๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ก,๐‘ก

0

= ๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) + ๐‘ก(โˆ’8๐œ‹2๐‘˜๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)

โˆ’ 2๐œ‹๐‘๐‘œ๐‘ (2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)2๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) + 2๐œ‹๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฆ)),

๐‘ฃ2 = ๐‘ฃ0 + โˆซ (โˆ’๐‘ฃ1๐‘ฃ1๐‘ฅ โˆ’ ๐‘ฃ1๐‘ฃ1๐‘ฆ + ๐‘˜(๐‘ฃ1๐‘ฅ๐‘ฅ + ๐‘ฃ1๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ก,๐‘ก

0

= ๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ 2๐œ‹2๐‘ก2๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)

โˆ’ 8๐œ‹2๐‘ก๐‘˜๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) + โ‹ฏ,

continue till n = 4, we get

๐‘ฃ4 = ๐‘ฃ0 + โˆซ (โˆ’๐‘ฃ3๐‘ฃ3๐‘ฅ โˆ’ ๐‘ฃ3๐‘ฃ3๐‘ฆ + ๐‘˜(๐‘ฃ3๐‘ฅ๐‘ฅ + ๐‘ฃ3๐‘ฆ๐‘ฆ)) ๐‘‘๐‘ก,๐‘ก

0

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= ๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ 2๐œ‹2๐‘ก2๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)

+2

3๐œ‹4๐‘ก4๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ)๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ) โˆ’ โ‹ฏ,

The obtained series solution in Eq. (3.28) can be used to calculate the

maximal error remainder to check the accuracy of the obtained approximate

solution. It can be clearly seen in table 3.3 and figure 3.2 that by increasing

the iterations the errors will be reduced.

Table 3.3: The maximal error remainder: ๐‘€๐ธ๐‘…๐‘› by the BCM.

n ๐‘ด๐‘ฌ๐‘น๐’ by BCM

1 1.61705 ร— 10โˆ’2

2 2.52036 ร— 10โˆ’5

3 3.56783 ร— 10โˆ’8

4 4.5361 ร— 10โˆ’11

Figure 3.2: Logarithmic plots of ๐‘€๐ธ๐‘…๐‘›versus ๐‘› is 1 through 4 by BCM.

Example 3.8:

Recall example 2.7:

๐‘ฃ๐‘ก = ๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ , with initial condition ๐‘ฃ(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ. (3.31)

By taking the integration for both sides of Eq. (3.31) from 0 to ๐‘ก, we obtain

1.0 1.5 2.0 2.5 3.0 3.5 4.010 11

10 8

10 5

10 2

n

ME

Rn

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๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฅ + ๐‘ฆ + โˆซ (๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก,๐‘ก

0

(3.32)

Implementing the BCM for Eq. (3.32), we get

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) + ๐‘(๐‘ฃ),

where

๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฅ + ๐‘ฆ and ๐‘(๐‘ฃ) = โˆซ (๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก.๐‘ก

0

Thus, we have

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก)

= ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)

+ โˆซ (๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฅ + ๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฅ๐‘ฅ

๐‘ก

0

+ ๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก, ๐‘› = 1,2, โ€ฆ. (3.33)

Thus, we get

๐‘ฃ0 = ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฅ + ๐‘ฆ,

๐‘ฃ1 = ๐‘ฃ0 + โˆซ (๐‘ฃ0๐‘ฃ0๐‘ฅ + ๐‘ฃ0๐‘ฅ๐‘ฅ + ๐‘ฃ0๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก ๐‘ก

0

= ๐‘ฅ + ๐‘ฆ + (๐‘ฅ + ๐‘ฆ)๐‘ก,

๐‘ฃ2 = ๐‘ฃ0 + โˆซ (๐‘ฃ1๐‘ฃ1๐‘ฅ + ๐‘ฃ1๐‘ฅ๐‘ฅ + ๐‘ฃ1๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก,๐‘ก

0

= ๐‘ฅ + ๐‘ฆ + (๐‘ฅ + ๐‘ฆ)๐‘ก + (๐‘ฅ + ๐‘ฆ)๐‘ก2 +1

3(๐‘ฅ + ๐‘ฆ)๐‘ก3,

By continuing in this way, we have a series of the form:

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Chapter Three Banach Contraction Method for Solving Some

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๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก) ,

= (๐‘ฅ + ๐‘ฆ) + (๐‘ฅ + ๐‘ฆ)๐‘ก + (๐‘ฅ + ๐‘ฆ)๐‘ก2 + (๐‘ฅ + ๐‘ฆ)๐‘ก3 + โ‹ฏ, (3.34)

This series is convergent to the following exact solution [76]:

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) =๐‘ฅ + ๐‘ฆ

1 โˆ’ ๐‘ก= (๐‘ฅ + ๐‘ฆ) + (๐‘ฅ + ๐‘ฆ)๐‘ก + (๐‘ฅ + ๐‘ฆ)๐‘ก2 + (๐‘ฅ + ๐‘ฆ)๐‘ก3 + โ‹ฏ.

Example 3.9:

Recall example 2.8:

๐‘ฃ๐‘ก = ๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ + ๐‘ฃ๐‘ง๐‘ง,

with initial condition ๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง. (3.35)

Applying the integration on both sides of Eq. (3.35) from 0 to ๐‘ก and using the

initial condition at ๐‘ก = 0, we get

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘ฅ + ๐‘ฆ + ๐‘ง + โˆซ (๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ + ๐‘ฃ๐‘ง๐‘ง)๐‘ก

0

๐‘‘๐‘ก. (3.36)

๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘ฅ + ๐‘ฆ + ๐‘ง and ๐‘(๐‘ฃ) = โˆซ (๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ + ๐‘ฃ๐‘ง๐‘ง) ๐‘‘๐‘ก.๐‘ก

0

Now, applying the BCM for Eq. (3.36), we have

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) + ๐‘(๐‘ฃ),

where

๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘ฅ + ๐‘ฆ + ๐‘ง and ๐‘(๐‘ฃ) = โˆซ (๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ + ๐‘ฃ๐‘ง๐‘ง) ๐‘‘๐‘ก.๐‘ก

0

Thus, we get

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๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

+ โˆซ (๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)(๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก))๐‘ฅ

+ (๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก))๐‘ฅ๐‘ฅ

๐‘ก

0

+ (๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก))๐‘ฆ๐‘ฆ

+ (๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก))๐‘ง๐‘ง

) ๐‘‘๐‘ก, ๐‘› = 1,2,3, โ€ฆ .

Thus, we have

๐‘ฃ0 = ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘ฅ + ๐‘ฆ + ๐‘ง,

๐‘ฃ1 = ๐‘ฃ0 + โˆซ (๐‘ฃ0๐‘ฃ0๐‘ฅ + ๐‘ฃ0๐‘ฅ๐‘ฅ + ๐‘ฃ0๐‘ฆ๐‘ฆ + ๐‘ฃ0๐‘ง๐‘ง) ๐‘‘๐‘ก,๐‘ก

0

= ๐‘ฅ + ๐‘ฆ + ๐‘ง + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก,

๐‘ฃ2 = ๐‘ฃ0 + โˆซ (๐‘ฃ1๐‘ฃ1๐‘ฅ + ๐‘ฃ1๐‘ฅ๐‘ฅ + ๐‘ฃ1๐‘ฆ๐‘ฆ + ๐‘ฃ1๐‘ง๐‘ง) ๐‘‘๐‘ก,๐‘ก

0

= ๐‘ฅ + ๐‘ฆ + ๐‘ง + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2 +1

3(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3,

and so on, therefore we get the following series:

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) ,

= ๐‘ฅ + ๐‘ฆ + ๐‘ง + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2 + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3

+ โ‹ฏ,

This series converges to the exact solution [76]:

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) =๐‘ฅ + ๐‘ฆ + ๐‘ง

1 โˆ’ ๐‘ก,

= ๐‘ฅ + ๐‘ฆ + ๐‘ง + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2 + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3 + โ‹ฏ.

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3.5.5 Solving the nonlinear system of Burgersโ€™ equations by

using BCM

In this subsection, the BCM will be implemented to solve the first order

nonlinear Burgersโ€™ equation for the exact solutions for different types of

systems of Burgersโ€™ equations in 1D, 2D and 3D.

Example 3.10:

Rewrite the example 2.9 and solve it by BCM [50].

๐‘ข๐‘ก โˆ’ ๐‘ข๐‘ฅ๐‘ฅ โˆ’ 2๐‘ข๐‘ข๐‘ฅ + (๐‘ข๐‘ฃ)๐‘ฅ = 0,

๐‘ฃ๐‘ก โˆ’ ๐‘ฃ๐‘ฅ๐‘ฅ โˆ’ 2๐‘ฃ๐‘ฃ๐‘ฅ + (๐‘ข๐‘ฃ)๐‘ฅ = 0,

Subject to the initial conditions:

๐‘ข(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ), ๐‘ฃ(๐‘ฅ, 0) = ๐‘ ๐‘–๐‘›(๐‘ฅ). (3.37)

By solving Eq. (3.37), we get

๐‘ข(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ) + โˆซ (๐‘ข๐‘ฅ๐‘ฅ + 2๐‘ข๐‘ข๐‘ฅ โˆ’ (๐‘ข๐‘ฃ)๐‘ฅ) ๐‘‘๐‘ก,๐‘ก

0

๐‘ฃ(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ) + โˆซ (๐‘ฃ๐‘ฅ๐‘ฅ + 2๐‘ฃ๐‘ฃ๐‘ฅ โˆ’ (๐‘ข๐‘ฃ)๐‘ฅ) ๐‘‘๐‘ก,๐‘ก

0

(3.38)

To solve the system of Eq. (3.38) by using of the BCM, we have

๐‘ข(๐‘ฅ, ๐‘ก) = ๐‘”(๐‘ฅ, ๐‘ก) + ๐‘1(๐‘ข), ๐‘ฃ(๐‘ฅ, ๐‘ก) = ๐‘“(๐‘ฅ, ๐‘ก) + ๐‘2(๐‘ฃ),

where

๐‘”(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ) and ๐‘1(๐‘ข) = โˆซ (๐‘ข๐‘ฅ๐‘ฅ + 2๐‘ข๐‘ข๐‘ฅ โˆ’ (๐‘ข๐‘ฃ)๐‘ฅ)๐‘ก

0

๐‘‘๐‘ก,

๐‘“(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ) and ๐‘2(๐‘ฃ) = โˆซ (๐‘ฃ๐‘ฅ๐‘ฅ + 2๐‘ฃ๐‘ฃ๐‘ฅ โˆ’ (๐‘ข๐‘ฃ)๐‘ฅ) ๐‘‘๐‘ก.๐‘ก

0

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Thus

๐‘ข๐‘›(๐‘ฅ, ๐‘ก) = ๐‘ข0(๐‘ฅ, ๐‘ก)

+ โˆซ ((๐‘ข๐‘›โˆ’1(๐‘ฅ, ๐‘ก))๐‘ฅ๐‘ฅ

+ 2๐‘ข๐‘›โˆ’1(๐‘ฅ, ๐‘ก)(๐‘ข๐‘›โˆ’1(๐‘ฅ, ๐‘ก))๐‘ฅ

๐‘ก

0

โˆ’ (๐‘ข๐‘›โˆ’1(๐‘ฅ, ๐‘ก)๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ก))๐‘ฅ

) ๐‘‘๐‘ก, ๐‘› = 1,2, โ€ฆ .

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ก) = ๐‘ฃ0(๐‘ฅ, ๐‘ก)

+ โˆซ ((๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ก))๐‘ฅ๐‘ฅ

+ 2๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ก)(๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ก))๐‘ฅ

๐‘ก

0

โˆ’ (๐‘ข๐‘›โˆ’1(๐‘ฅ, ๐‘ก)๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ก))๐‘ฅ

) ๐‘‘๐‘ก, ๐‘› = 1,2, โ€ฆ . (3.39)

Then,

๐‘ข0 = ๐‘”(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ),

๐‘ฃ0 = ๐‘“(๐‘ฅ, ๐‘ก) = ๐‘ ๐‘–๐‘›(๐‘ฅ),

๐‘ข1 = ๐‘ข0 + โˆซ (๐‘ข0๐‘ฅ๐‘ฅ + 2๐‘ข0๐‘ข0๐‘ฅ โˆ’ (๐‘ข0๐‘ฃ0)๐‘ฅ) ๐‘‘๐‘ก๐‘ก

0

= ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ),

๐‘ฃ1 = ๐‘ฃ0 + โˆซ (๐‘ฃ0๐‘ฅ๐‘ฅ + 2๐‘ฃ0๐‘ฃ0๐‘ฅ โˆ’ (๐‘ข0๐‘ฃ0)๐‘ฅ) ๐‘‘๐‘ก๐‘ก

0

= ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ),

๐‘ข2 = ๐‘ข0 + โˆซ (๐‘ข1๐‘ฅ๐‘ฅ + 2๐‘ข1๐‘ข1๐‘ฅ โˆ’ (๐‘ข1๐‘ฃ1)๐‘ฅ) ๐‘‘๐‘ก,๐‘ก

0

= ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) +1

2๐‘ก2๐‘ ๐‘–๐‘›(๐‘ฅ),

๐‘ฃ2 = ๐‘ฃ0 + โˆซ (๐‘ฃ1๐‘ฅ๐‘ฅ + 2๐‘ฃ1๐‘ฃ1๐‘ฅ โˆ’ (๐‘ข1๐‘ฃ1)๐‘ฅ) ๐‘‘๐‘ก,๐‘ก

0

= ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) +1

2๐‘ก2๐‘ ๐‘–๐‘›(๐‘ฅ),

Continuing in this way, we get:

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๐‘ข(๐‘ฅ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘›(๐‘ฅ, ๐‘ก) ,

= ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) +1

2๐‘ก2๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’

1

6๐‘ก3๐‘ ๐‘–๐‘›(๐‘ฅ) +

1

24๐‘ก4๐‘ ๐‘–๐‘›(๐‘ฅ)

โˆ’ โ‹ฏ,

๐‘ฃ(๐‘ฅ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ก) ,

= ๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’ ๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ) +1

2๐‘ก2๐‘ ๐‘–๐‘›(๐‘ฅ) โˆ’

1

6๐‘ก3๐‘ ๐‘–๐‘›(๐‘ฅ) +

1

24๐‘ก4๐‘ ๐‘–๐‘›(๐‘ฅ)

โˆ’ โ‹ฏ.

This series converges to the exact solution [50]:

๐‘ข(๐‘ฅ, ๐‘ก) = โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ),

๐‘ฃ(๐‘ฅ, ๐‘ก) = โ…‡โˆ’๐‘ก๐‘ ๐‘–๐‘›(๐‘ฅ).

Example 3.11:

Rewrite the example 2.10 and solve it by BCM [30].

๐‘ข๐‘ก + ๐‘ข๐‘ข๐‘ฅ + ๐‘ฃ๐‘ข๐‘ฆ โˆ’ ๐‘ข๐‘ฅ๐‘ฅ โˆ’ ๐‘ข๐‘ฆ๐‘ฆ = 0,

๐‘ฃ๐‘ก + ๐‘ข๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ โˆ’ ๐‘ฃ๐‘ฅ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฆ๐‘ฆ = 0,

Subject to the initial conditions:

๐‘ข(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ + ๐‘ฆ, ๐‘ฃ(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ฅ โˆ’ ๐‘ฆ. (3.40)

Integrating both sides of Eq. (3.40) from 0 to ๐‘ก and using the initial conditions

at ๐‘ก = 0, we get

๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฅ + ๐‘ฆ + โˆซ (โˆ’๐‘ข๐‘ข๐‘ฅ โˆ’ ๐‘ฃ๐‘ข๐‘ฆ + ๐‘ข๐‘ฅ๐‘ฅ + ๐‘ข๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก,๐‘ก

0

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฅ โˆ’ ๐‘ฆ + โˆซ (โˆ’๐‘ข๐‘ฃ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฃ๐‘ฆ + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก๐‘ก

0

, (3.41)

To solve the system of Eq. (3.41) by using of the BCM

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๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ก) + ๐‘1(๐‘ข), ๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) + ๐‘2(๐‘ฃ)

where

๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฅ + ๐‘ฆ and ๐‘1(๐‘ข) = โˆซ (โˆ’๐‘ข๐‘ข๐‘ฅ โˆ’ ๐‘ฃ๐‘ข๐‘ฆ + ๐‘ข๐‘ฅ๐‘ฅ + ๐‘ข๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก,๐‘ก

0

๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฅ โˆ’ ๐‘ฆ and ๐‘2(๐‘ฃ) = โˆซ (โˆ’๐‘ข๐‘ฃ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฃ๐‘ฆ + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก๐‘ก

0

.

Thus

๐‘ข๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก)

= ๐‘ข0(๐‘ฅ, ๐‘ฆ, ๐‘ก)

+ โˆซ (โˆ’๐‘ข๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)(๐‘ข๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก))๐‘ฅ

๐‘ก

0

โˆ’ ๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)(๐‘ข๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก))๐‘ฆ

+ (๐‘ข๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก))๐‘ฅ๐‘ฅ

+ (๐‘ข๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก))๐‘ฆ๐‘ฆ

) ๐‘‘๐‘ก, ๐‘› = 1,2, โ€ฆ,

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก)

= ๐‘ฃ0(๐‘ฅ, ๐‘ฆ, ๐‘ก)

+ โˆซ (โˆ’๐‘ข๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)(๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก))๐‘ฅ

๐‘ก

0

โˆ’ ๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก)(๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก))๐‘ฆ

+ (๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก))๐‘ฅ๐‘ฅ

+ (๐‘ฃ๐‘›โˆ’1(๐‘ฅ, ๐‘ฆ, ๐‘ก))๐‘ฆ๐‘ฆ

) ๐‘‘๐‘ก, ๐‘› = 1,2, โ€ฆ. (3.42)

Therefore, we have

๐‘ข0 = ๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฅ + ๐‘ฆ,

๐‘ฃ0 = ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘ฅ โˆ’ ๐‘ฆ,

๐‘ข1 = ๐‘ข0 + โˆซ (โˆ’๐‘ข0๐‘ข0๐‘ฅ โˆ’ ๐‘ฃ0๐‘ข0๐‘ฆ + ๐‘ข0๐‘ฅ๐‘ฅ + ๐‘ข0๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก๐‘ก

0

= ๐‘ฅ + ๐‘ฆ โˆ’ 2๐‘ฅ๐‘ก,

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๐‘ฃ1 = ๐‘ฃ0 + โˆซ (โˆ’๐‘ข0๐‘ฃ0๐‘ฅ โˆ’ ๐‘ฃ0๐‘ฃ0๐‘ฆ + ๐‘ฃ0๐‘ฅ๐‘ฅ + ๐‘ฃ0๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก๐‘ก

0

= ๐‘ฅ โˆ’ ๐‘ฆ โˆ’ 2๐‘ฆ๐‘ก,

๐‘ข2 = ๐‘ข0 + โˆซ (โˆ’๐‘ข1๐‘ข1๐‘ฅ โˆ’ ๐‘ฃ1๐‘ข1๐‘ฆ + ๐‘ข1๐‘ฅ๐‘ฅ + ๐‘ข1๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก,๐‘ก

0

= ๐‘ฅ + ๐‘ฆ โˆ’ 2๐‘ฅ๐‘ก + 2(๐‘ฅ + ๐‘ฆ)๐‘ก2 โˆ’4๐‘ฅ๐‘ก3

3,

๐‘ฃ2 = ๐‘ฃ0 + โˆซ (โˆ’๐‘ข1๐‘ฃ1๐‘ฅ โˆ’ ๐‘ฃ1๐‘ฃ1๐‘ฆ + ๐‘ฃ1๐‘ฅ๐‘ฅ + ๐‘ฃ1๐‘ฆ๐‘ฆ) ๐‘‘๐‘ก,๐‘ก

0

= ๐‘ฅ โˆ’ ๐‘ฆ โˆ’ 2๐‘ฆ๐‘ก + (2๐‘ฅ โˆ’ 2๐‘ฆ)๐‘ก2 โˆ’4๐‘ฆ๐‘ก3

3,

Continuing in this way, we get the following forms:

๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก) ,

= ๐‘ฅ + ๐‘ฆ โˆ’ 2๐‘ฅ๐‘ก + 2(๐‘ฅ + ๐‘ฆ)๐‘ก2 โˆ’ 4๐‘ฅ๐‘ก3 + 4(๐‘ฅ + ๐‘ฆ)๐‘ก4 โˆ’ 8๐‘ฅ๐‘ก5

+ โ‹ฏ,

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ก) ,

= ๐‘ฅ โˆ’ ๐‘ฆ โˆ’ 2๐‘ฆ๐‘ก + (2๐‘ฅ โˆ’ 2๐‘ฆ)๐‘ก2 โˆ’ 4๐‘ฆ๐‘ก3 + (4๐‘ฅ โˆ’ 4๐‘ฆ)๐‘ก4 โˆ’ 8๐‘ฆ๐‘ก5

+ โ‹ฏ.

These forms converges to the exact solutions [30]:

๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ก) =๐‘ฅ โˆ’ 2๐‘ฅ๐‘ก + ๐‘ฆ

1 โˆ’ 2๐‘ก2,

= ๐‘ฅ + ๐‘ฆ โˆ’ 2๐‘ฅ๐‘ก + 2(๐‘ฅ + ๐‘ฆ)๐‘ก2 โˆ’ 4๐‘ฅ๐‘ก3 + 4(๐‘ฅ + ๐‘ฆ)๐‘ก4 โˆ’ 8๐‘ฅ๐‘ก5 + โ‹ฏ,

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ก) =๐‘ฅ โˆ’ 2๐‘ฆ๐‘ก โˆ’ ๐‘ฆ

1 โˆ’ 2๐‘ก2,

= ๐‘ฅ โˆ’ ๐‘ฆ โˆ’ 2๐‘ฆ๐‘ก + (2๐‘ฅ โˆ’ 2๐‘ฆ)๐‘ก2 โˆ’ 4๐‘ฆ๐‘ก3 + (4๐‘ฅ โˆ’ 4๐‘ฆ)๐‘ก4 โˆ’ 8๐‘ฆ๐‘ก5 + โ‹ฏ.

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Example 3.12:

Recall example 2.11:

๐‘ข๐‘ก โˆ’ ๐‘ข๐‘ข๐‘ฅ โˆ’ ๐‘ฃ๐‘ข๐‘ฆ โˆ’ ๐‘ค๐‘ข๐‘ง โˆ’ ๐‘ข๐‘ฅ๐‘ฅ โˆ’ ๐‘ข๐‘ฆ๐‘ฆ โˆ’ ๐‘ข๐‘ง๐‘ง = ๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก),

๐‘ฃ๐‘ก + ๐‘ข๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ + ๐‘ค๐‘ฃ๐‘ง + ๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ + ๐‘ฃ๐‘ง๐‘ง = ๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก),

๐‘ค๐‘ก + ๐‘ข๐‘ค๐‘ฅ + ๐‘ฃ๐‘ค๐‘ฆ + ๐‘ค๐‘ค๐‘ง + ๐‘ค๐‘ฅ๐‘ฅ + ๐‘ค๐‘ฆ๐‘ฆ + ๐‘ค๐‘ง๐‘ง = โ„Ž(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก),

where

๐‘”(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) โˆ’ โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)),

๐‘“(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โˆ’โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) โˆ’ โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)),

โ„Ž(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง) + โ…‡๐‘ก(1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง)), (3.43)

Subject to the initial conditions:

๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = ๐‘ฅ + ๐‘ฆ + ๐‘ง,

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = โˆ’(๐‘ฅ + ๐‘ฆ + ๐‘ง),

๐‘ค(๐‘ฅ, ๐‘ฆ, ๐‘ง, 0) = 1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง.

Integrating both sides of in Eq. (3.43) from 0 to ๐‘ก and using the initial

conditions at ๐‘ก = 0, we get

๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= 1 โˆ’ โ…‡๐‘ก +๐‘ฅ

2+ โ…‡๐‘ก๐‘ฅ โˆ’

1

2โ…‡2๐‘ก๐‘ฅ +

๐‘ฆ

2+ โ…‡๐‘ก๐‘ฆ โˆ’

1

2โ…‡2๐‘ก๐‘ฆ +

๐‘ง

2+ โ…‡๐‘ก๐‘ง

โˆ’1

2โ…‡2๐‘ก๐‘ง + โˆซ (๐‘ข๐‘ข๐‘ฅ + ๐‘ฃ๐‘ข๐‘ฆ + ๐‘ค๐‘ข๐‘ง + ๐‘ข๐‘ฅ๐‘ฅ + ๐‘ข๐‘ฆ๐‘ฆ + ๐‘ข๐‘ง๐‘ง) ๐‘‘๐‘ก,

๐‘ก

0

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๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= 1 โˆ’ โ…‡๐‘ก +๐‘ฅ

2โˆ’ โ…‡๐‘ก๐‘ฅ โˆ’

1

2โ…‡2๐‘ก๐‘ฅ +

๐‘ฆ

2โˆ’ โ…‡๐‘ก๐‘ฆ โˆ’

1

2โ…‡2๐‘ก๐‘ฆ +

๐‘ง

2โˆ’ โ…‡๐‘ก๐‘ง

โˆ’1

2โ…‡2๐‘ก๐‘ง + โˆซ (โˆ’๐‘ข๐‘ฃ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฃ๐‘ฆ โˆ’ ๐‘ค๐‘ฃ๐‘ง โˆ’ ๐‘ฃ๐‘ฅ๐‘ฅ โˆ’ ๐‘ฃ๐‘ฆ๐‘ฆ โˆ’ ๐‘ฃ๐‘ง๐‘ง) ๐‘‘๐‘ก,

๐‘ก

0

๐‘ค(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก)

= โ…‡๐‘ก โˆ’๐‘ฅ

2+ โ…‡๐‘ก๐‘ฅ +

1

2โ…‡2๐‘ก๐‘ฅ โˆ’

๐‘ฆ

2+ โ…‡๐‘ก๐‘ฆ +

1

2โ…‡2๐‘ก๐‘ฆ โˆ’

๐‘ง

2+ โ…‡๐‘ก๐‘ง +

1

2โ…‡2๐‘ก

+ โˆซ (โˆ’๐‘ข๐‘ค๐‘ฅ โˆ’ ๐‘ฃ๐‘ค๐‘ฆ โˆ’ ๐‘ค๐‘ค๐‘ง โˆ’ ๐‘ค๐‘ฅ๐‘ฅ โˆ’ ๐‘ค๐‘ฆ๐‘ฆ โˆ’ ๐‘ค๐‘ง๐‘ง) ๐‘‘๐‘ก,๐‘ก

0

(3.44)

To solve the system of Eq. (3.44) by using of the BCM, we have

๐‘ข0 = 1 โˆ’ โ…‡๐‘ก +๐‘ฅ

2+ โ…‡๐‘ก๐‘ฅ โˆ’

1

2โ…‡2๐‘ก๐‘ฅ +

๐‘ฆ

2+ โ…‡๐‘ก๐‘ฆ โˆ’

1

2โ…‡2๐‘ก๐‘ฆ +

๐‘ง

2+ โ…‡๐‘ก๐‘ง โˆ’

1

2โ…‡2๐‘ก๐‘ง,

๐‘ฃ0 = 1 โˆ’ โ…‡๐‘ก +๐‘ฅ

2โˆ’ โ…‡๐‘ก๐‘ฅ โˆ’

1

2โ…‡2๐‘ก๐‘ฅ +

๐‘ฆ

2โˆ’ โ…‡๐‘ก๐‘ฆ โˆ’

1

2โ…‡2๐‘ก๐‘ฆ +

๐‘ง

2โˆ’ โ…‡๐‘ก๐‘ง โˆ’

1

2โ…‡2๐‘ก๐‘ง,

๐‘ค0 = โ…‡๐‘ก โˆ’๐‘ฅ

2+ โ…‡๐‘ก๐‘ฅ +

1

2โ…‡2๐‘ก๐‘ฅ โˆ’

๐‘ฆ

2+ โ…‡๐‘ก๐‘ฆ +

1

2โ…‡2๐‘ก๐‘ฆ โˆ’

๐‘ง

2+ โ…‡๐‘ก๐‘ง +

1

2โ…‡2๐‘ก ,

By writing the functions ๐‘ข1, ๐‘ฃ1, ๐‘ค1 by using Taylor series expansions, we get

๐‘ข1 = (๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(โˆ’2 โˆ’ ๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก2 +

1

6(โˆ’3 โˆ’ 5๐‘ฅ

โˆ’ 5๐‘ฆ โˆ’ 5๐‘ง)๐‘ก3 +1

24(โˆ’2 โˆ’ 13๐‘ฅ โˆ’ 13๐‘ฆ โˆ’ 13๐‘ง)๐‘ก4 +

1

120(9

โˆ’ 23๐‘ฅ โˆ’ 23๐‘ฆ โˆ’ 23๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6,

๐‘ฃ1 = (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง) + (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก +1

2(โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก2

+1

2(โˆ’1 โˆ’ ๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก3 +

1

24(โˆ’12 โˆ’ 13๐‘ฅ โˆ’ 13๐‘ฆ โˆ’ 13๐‘ง)๐‘ก4

+1

40(โˆ’13 โˆ’ 19๐‘ฅ โˆ’ 19๐‘ฆ โˆ’ 19๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6,

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๐‘ค1 = (1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2

+1

2(1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3 +

1

24(12 + 13๐‘ฅ + 13๐‘ฆ + 13๐‘ง)๐‘ก4

+1

40(13 + 19๐‘ฅ + 19๐‘ฆ + 19๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6. (3.45)

In a similar way, we have

๐‘ข2 = (๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2 +

1

6(โˆ’4 โˆ’ 3๐‘ฅ โˆ’ 3๐‘ฆ

โˆ’ 3๐‘ง)๐‘ก3 +1

24(โˆ’15 โˆ’ 23๐‘ฅ โˆ’ 23๐‘ฆ โˆ’ 23๐‘ง)๐‘ก4 +

1

120(โˆ’16 โˆ’ 75๐‘ฅ

โˆ’ 75๐‘ฆ โˆ’ 75๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6,

๐‘ฃ2 = (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง) + (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก +1

2(โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก2 +

1

6(โˆ’2 โˆ’ 3๐‘ฅ

โˆ’ 3๐‘ฆ โˆ’ 3๐‘ง)๐‘ก3 +1

24(โˆ’7 โˆ’ 11๐‘ฅ โˆ’ 11๐‘ฆ โˆ’ 11๐‘ง)๐‘ก4 +

1

120(โˆ’14

โˆ’ 31๐‘ฅ โˆ’ 31๐‘ฆ โˆ’ 31๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6,

๐‘ค2 = (1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง) + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2

+1

6(2 + 3๐‘ฅ + 3๐‘ฆ + 3๐‘ง)๐‘ก3 +

1

24(7 + 11๐‘ฅ + 11๐‘ฆ + 11๐‘ง)๐‘ก4

+1

120(14 + 31๐‘ฅ + 31๐‘ฆ + 31๐‘ง)๐‘ก5 + ๐‘‚[๐‘ก]6. (3.46)

By continuing, we have the following formulas:

๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ข๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) ,

= ๐‘ฅ + ๐‘ฆ + ๐‘ง + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2

+1

6(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3 + โ‹ฏ,

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ฃ๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) ,

= โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง + (โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก +1

2(โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก2

+1

6(โˆ’๐‘ฅ โˆ’ ๐‘ฆ โˆ’ ๐‘ง)๐‘ก3 + โ‹ฏ,

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Chapter Three Banach Contraction Method for Solving Some

Ordinary and Partial Differential Equations

116

๐‘ค(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = ๐‘™๐‘–๐‘š๐‘› โ†’ โˆž

๐‘ค๐‘›(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) ,

= 1 + ๐‘ฅ + ๐‘ฆ + ๐‘ง + (๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก +1

2(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก2

+1

6(๐‘ฅ + ๐‘ฆ + ๐‘ง)๐‘ก3 + โ‹ฏ.

Those forms converge to the following exact solutions:

๐‘ข(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง),

๐‘ฃ(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = โˆ’โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง),

๐‘ค(๐‘ฅ, ๐‘ฆ, ๐‘ง, ๐‘ก) = 1 + โ…‡๐‘ก(๐‘ฅ + ๐‘ฆ + ๐‘ง).

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CHAPTER 4

CONCLUSIONS AND FUTURE

WORKS

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Chapter Four Conclusions and Future Works

117

Chapter 4

Conclusions and Future Works

4.1 Introduction

The main objective of this thesis has been achieved by solving some of

non-linear ODE and PDE by different iterative methods. This purpose has

been obtained by implementing two iterative methods, which are so-called the

semi-analytic method of TAM and BCM. In addition, the comparison

between the proposed methods and other methods such as ADM and VIM

will be presented. Also, some conclusions, and future works will be given.

4.2 Conclusions

From the present study one can conclude the following:

1. The two iterative methods are efficient and reliable to find the exact

solutions for Riccati and pantograph equations, different types of Burgersโ€™

equations and equations systems in 1D, 2D and 3D. The efficiency and

accuracy of the TAM has been proved by studying the convergence.

2. The two proposed methods did not require any resulted assumption to deal

with the nonlinear terms unlike ADM was need the so-called Adomain

polynomial in nonlinear case. In addition, the VIM required the Lagrange

multiplier.

3. We take example for nonlinear Riccati equation it was solved in chapter 1,

chapter 2 and chapter 3

๐‘ฃโ€ฒ = โˆ’๐‘ฃ2 + 1, with initial condition ๐‘ฃ(0) = 0. (4.1)

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Chapter Four Conclusions and Future Works

118

When comparing the results of TAM and BCM with those of the ADM

and VIM, the numerical solutions obtained by BCM are more accurate.

The maximal error remainders will be decreased when there is more

obtaining of iterations which are clarified in the figure 4.1 and table 4.1.

Table 4.1: Comparative results of the maximal error remainder: ๐‘€๐ธ๐‘…๐‘›for

TAM, BCM, VIM and ADM, where ๐‘› = 1, โ€ฆ ,6.

n ๐‘ด๐‘ฌ๐‘น๐’ by TAM ๐‘ด๐‘ฌ๐‘น๐’ by BCM ๐‘ด๐‘ฌ๐‘น๐’by VIM ๐‘ด๐‘ฌ๐‘น๐’by ADM

1 6.65556 ร— 10โˆ’5 6.65556 ร— 10โˆ’5 0.01 6.65556 ร— 10โˆ’5

2 2.65463 ร— 10โˆ’7 2.65463 ร— 10โˆ’7 6.65556 ร— 10โˆ’5 3.76891 ร— 10โˆ’7

3 7.56708 ร— 10โˆ’10 7.56708 ร— 10โˆ’10 2.65463 ร— 10โˆ’7 1.96289 ร— 10โˆ’9

4 1.67806 ร— 10โˆ’12 1.67808 ร— 10โˆ’12 7.56708 ร— 10โˆ’10 9.72067 ร— 10โˆ’12

5 2.97852 ร— 10โˆ’15 3.04791 ร— 10โˆ’15 1.67808 ร— 10โˆ’12 4.65513 ร— 10โˆ’14

6 1.24033 ร— 10โˆ’16 3.46945 ร— 10โˆ’18 3.04791ร— 10โˆ’15 2.15106 ร— 10โˆ’16

Figure 4.1: Comparison of the maximal error remainder for TAM, BCM,

VIM and ADM.

4. We take example for nonlinear beam equation it was solved in chapter 1,

chapter 2 and chapter 3

๐‘ฃ(4) = ๐‘ฃ2 โˆ’ ๐‘ฅ10 + 4๐‘ฅ9 โˆ’ 4๐‘ฅ8 โˆ’ 4๐‘ฅ7 + 8๐‘ฅ6 โˆ’ 4๐‘ฅ4 + 120๐‘ฅ โˆ’ 48,

with the boundary conditions ๐‘ฃ(0) = ๐‘ฃโ€ฒ(0) = 0, ๐‘ฃ(1) = ๐‘ฃโ€ฒ(1) = 1. (4.2)

1 2 3 4 5 6

10 20.020.03

n

ME

Rn

ADM

VIM

BCM

TAM

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Chapter Four Conclusions and Future Works

119

In comparison the results by the TAM and BCM with the some existing

methods such as VIM and HPM [1], it is observed in general that the

approximate solutions obtained by the TAM converge faster without any

restricted assumptions and possesses high-order accuracy. As given in

table 4.2, we compare the absolute error of TAM, with n = 2 together with

the VIM, and the HPM [1].

Table 4.2: Comparative results for the absolute errors of the TAM, BCM,

VIM and HPM.

x |๐’“๐Ÿ| for TAM |๐’“๐Ÿ| for BCM |๐’“๐Ÿ| for VIM |๐’“๐Ÿ|for HPM[1]

0 0 0 0 0

0.1 1.77279 ร— 10โˆ’10 6.79965 ร— 10โˆ’9 6.79965 ร— 10โˆ’9 1.896 ร— 10โˆ’7

0.2 5.99375 ร— 10โˆ’10 2.3887 ร— 10โˆ’8 2.3887 ร— 10โˆ’8 6.4171 ร— 10โˆ’7

0.3 1.1028 ร— 10โˆ’9 4.62946 ร— 10โˆ’8 4.62946 ร— 10โˆ’8 1.18180 ร— 10โˆ’6

0.4 1.53129 ร— 10โˆ’9 6.90558 ร— 10โˆ’8 6.90558 ร— 10โˆ’8 1.6405 ร— 10โˆ’6

0.5 1.752 ร— 10โˆ’9 8.72068 ร— 10โˆ’8 8.72068 ร— 10โˆ’8 1.8703 ร— 10โˆ’6

0.6 1.68284 ร— 10โˆ’9 9.58101ร— 10โˆ’8 9.58101 ร— 10โˆ’8 1.7815 ร— 10โˆ’6

0.7 1.32351ร— 10โˆ’9 9.01332 ร— 10โˆ’8 9.01332 ร— 10โˆ’8 1.3816 ร— 10โˆ’6

0.8 7.76486 ร— 10โˆ’10 6.67054 ร— 10โˆ’8 6.67054 ร— 10โˆ’8 7.958 ร— 10โˆ’7

0.9 2.44241ร— 10โˆ’10 2.80674 ร— 10โˆ’8 2.80674 ร— 10โˆ’8 2.437 ร— 10โˆ’7

1.0 1.11022 ร— 10โˆ’16 0 0 6.0 ร— 10โˆ’10

It can be observed clearly from table 4.2, the absolute error for TAM is lower

than BCM, VIM and HPM.

5. We take example for nonlinear 2D Burgersโ€™ equation it was solved in

chapter 1, chapter 2 and chapter 3

๐‘ฃ๐‘ก + ๐‘ฃ๐‘ฃ๐‘ฅ + ๐‘ฃ๐‘ฃ๐‘ฆ = ๐‘˜(๐‘ฃ๐‘ฅ๐‘ฅ + ๐‘ฃ๐‘ฆ๐‘ฆ), (4.3)

with initial condition ๐‘ฃ(๐‘ฅ, ๐‘ฆ, 0) = ๐‘ ๐‘–๐‘›(2๐œ‹๐‘ฅ)๐‘๐‘œ๐‘ (2๐œ‹๐‘ฆ).

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Chapter Four Conclusions and Future Works

120

The TAM has also achieved the rapid convergence of our approximate

solution by the sequence of the curves of error remainder functions. Also

it does not require any restricted assumptions like the ADM and VIM,

which are clarified in the mentioned figure 4.2 and table 4.3.

Table 4.3: Comparative results the maximal error remainder: ๐‘€๐ธ๐‘…๐‘› for

TAM, BCM, VIM and ADM, where ๐‘› = 1, โ€ฆ ,4.

n ๐‘ด๐‘ฌ๐‘น๐’ by TAM ๐‘ด๐‘ฌ๐‘น๐’ by BCM ๐‘ด๐‘ฌ๐‘น๐’by VIM ๐‘ด๐‘ฌ๐‘น๐’ by ADM

1 5.99981 ร— 10โˆ’3 1.61705 ร— 10โˆ’2 1.61705 ร— 10โˆ’2 1.61705 ร— 10โˆ’2

2 2.89069 ร— 10โˆ’6 2.52036 ร— 10โˆ’5 2.52036 ร— 10โˆ’5 2.98775 ร— 10โˆ’5

3 1.12531 ร— 10โˆ’8 3.56783 ร— 10โˆ’8 3.56783 ร— 10โˆ’8 4.9464 ร— 10โˆ’8

4 4.54397 ร— 10โˆ’11 4.5361 ร— 10โˆ’11 4.53593 ร— 10โˆ’11 7.1962 ร— 10โˆ’11

Figure 4.2: Comparison of the maximal error remainder for TAM, BCM,

VIM and ADM.

6. The analytic solutions of these different problems are excellent as

compared to the results of other iterative methods. In nonlinear equations

that emerge much of the time to express phenomenon the proposed

methods are effective and strong enough to give the reliable results.

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Chapter Four Conclusions and Future Works

121

4.3 Future works

In this section some of future works will be suggested

1) Solving the Emdenโ€“Fowler equation by using TAM

๐‘ฃโ€ฒโ€ฒ +๐‘˜

๐‘ฅ ๐‘ฃโ€ฒ + ๐‘“(๐‘ฅ)๐‘”(๐‘ฃ) = 0, ๐‘ฃ(0) = ๐‘ฃ0, ๐‘ฃโ€ฒ(0) = 0, (4.4)

where ๐‘“(๐‘ฅ) and ๐‘”(๐‘ฃ) are some given functions of ๐‘ฅ and ๐‘ฃ, respectively,

and ๐‘˜ is called the shape factor.

2) Using BCM for solving a Thomas-Fermi equation

๐‘ฃโ€ฒโ€ฒ =๐‘ฃ

32

โˆš๐‘ฅ, ๐‘ฃ(0) = 1, ๐‘ฃ(โˆž) = 0, (4.5)

3) Solving the Blasius equation by using TAM

๐‘ฃโ€ฒโ€ฒโ€ฒ +1

2๐‘ฃ๐‘ฃโ€ฒโ€ฒ = 0, ๐‘ฃ(0) = 0, ๐‘ฃโ€ฒ(0) = 1, ๐‘ฃโ€ฒโ€ฒ(0) = ๐›ผ, ๐›ผ > 0. (4.6)

4) Solving the sine-Gordon equation by using TAM

๐‘ฃ๐‘ก๐‘ก โˆ’ ๐‘2๐‘ฃ๐‘ฅ๐‘ฅ + ๐›ผ sin(๐‘ฃ) = 0, ๐‘ฃ(๐‘ฅ, 0) = ๐‘“(๐‘ฅ), ๐‘ฃ๐‘ก(๐‘ฅ, 0) = ๐‘”(๐‘ฅ), (4.7)

where ๐‘ and ๐›ผ are constants. It is clear that this equation adds the

nonlinear term sin(๐‘ฃ) to the standard wave equation.

5) Using BCM for solving the telegraph equation

๐‘ฃ๐‘ฅ๐‘ฅ = ๐‘Ž๐‘ฃ๐‘ก๐‘ก + ๐‘๐‘ฃ๐‘ก + ๐‘๐‘ฃ, ๐‘ฃ(๐‘ฅ, 0) = ๐‘“(๐‘ฅ), ๐‘ฃ๐‘ก(๐‘ฅ, 0) = ๐‘”(๐‘ฅ), (4.8)

where ๐‘ฃ = ๐‘ฃ(๐‘ฅ, ๐‘ก) is the resistance, and ๐‘Ž, ๐‘ and c are constants related to

the inductance, capacitance and conductance of the cable respectively.

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REFERENCES

Page 143: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

References

122

REFERENCES

[1] A. Barari, B. Ganjavi, M. G. Jeloudar, G. Domairry, "Assessment of

two analytical methods in solving the linear and nonlinear elastic beam

deformation problems", Journal of Engineering, Design and

Technology 8 (2), 127โ€“145, (2010).

[2] A. K. Alomari, M. S. M. Noorani, R. Nazar, "The Homotopy Analysis

Method for the Exact Solutions of the K(2,2), Burgersโ€™ and Coupled

Burgersโ€™ Equations", Applied Mathematical Sciences 2 (40), 1963โ€“

1977, (2008).

[3] A. Latif, "Banach Contraction Principle and Its Generalizations",

Springer International Publishing Switzerland 2014, 33โ€“46, (2014).

[4] A. M. Wazwaz, "The variational iteration method for solving linear and

nonlinear ODEs and scientific models with variable coefficients",

Central European Journal of Engineering 4 (1), 64โ€“71, (2014).

[5] A. M. Wazwaz, "Partial Differential Equations: Methods and

Applications", (2002).

[6] A. M. Wazwaz, "Linear and nonlinear integral equations", Springer

Heidelberg Dordrecht London New York, (2011).

[7] A. M. Wazwaz, "Partial differential equations and solitary waves

theory", Higher Education Press, Beijing, and Springer-Verlag, Berlin,

(2009).

[8] A. M. Wazwaz, "The variational iteration method for exact solutions of

Laplace equation", Physics letters 363, 260โ€“262, (2007).

[9] A. M. Wazwaz, "The variational iteration method for solving two forms

of Blasius equation on a half-infinite domain", Applied Mathematics

and Computations 188, 485โ€“491, (2007).

[10] A. Naghipour, J. Manafian, "Application of the Laplace Adomian

Decomposition and Implicit Methods for Solving Burgersโ€™ Equation",

TWMS Journal of Pure and Applied Mathematics 6 (1), 68โ€“77, (2015).

[11] A. Saadatmandi, M. Dehghanb, "Variational iteration method for

solving a generalized pantograph equation", Computers and

Mathematics with Applications 58 (11โ€“12), 2190โ€“2196, (2009).

Page 144: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

References

123

[12] B. D. Anderson, J. B. Moore, "Optimal control-linear quadratic

methods", Prentice-Hall, New Jersey, (1999).

[13] B. Lin, K. Li, "The (1 + 3)-dimensional Burgersโ€™ equation and its

comparative solutions", Journal of Computers and Mathematics with

Applications 60, 3082โ€“3087, (2010).

[14] D. J. Evans, K. R. Raslan, "The Adomian decomposition method for

solving delay differential equation", International Journal of Computer

Mathematics 82 (1), 49โ€“54, (2005).

[15] E. H. Doha, A. H. Bhrawy, D. Baleanu, R. M. Hafez, "A new Jacobi

rationalโ€“Gauss collocation method for numerical solution of

generalized pantograph equations", Applied Numerical Mathematics

77, 43โ€“54, (2014).

[16] E. Yusufoห˜glu, "An efficient algorithm for solving generalized

pantograph equations with linear functional argument", Applied

Mathematics and Computation 217, 3591โ€“3595, (2010).

[17] F. A. Alhendi, A. A. Alderremy, "Numerical Solutions of Three-

Dimensional Coupled Burgersโ€™ Equations by Using Some Numerical

Methods", Journal of Applied Mathematics and Physics 4, 2011โ€“2030,

(2016).

[18] F. Ehsani, A. Hadi, F. Ehsani, R. Mahdavi, "An iterative method for

solving partial differential equations and solution of Korteweg-de Vries

equations for showing the capability of the iterative method", World

Applied Programming 3 (8), 320โ€“327, (2013).

[19] F. Ghomanjani, E. Khorrama, "Approximate solution for quadratic

Riccati differential equation", Journal of Taibah University for

Science 11 (2), 246โ€“250, (2017).

[20] F. Genga, Y. Lin, M. Cui, "A piecewise variational iteration method for

Riccati differential equations", Computers and Mathematics with

Applications 58 (11โ€“12), 2518โ€“2522, (2009).

[21] F. Liu, S. Weiping, "Numerical solutions of two-dimensional Burgersโ€™

equations by lattice Boltzmann method", Communications in Nonlinear

Science and Numerical 16 (1), 150โ€“157, (2011).

[22] G. Adomian, "Solving frontier problems in physics: the decomposition

method", Kluwer Academic, Boston, (1994).

Page 145: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

References

124

[23] G. Adomian. "Nonlinear Stochastic Operator Equations", Academic.

Orlando, (1986).

[24] G. Adomian, R. Rach. "Inversion of nonlinear stochastic operators",

Journal of Mathematical Analysis and Applications 91, 39โ€“46, (1983).

[25] G. Adomian, R. Rach, "Solving nonlinear differential equations with

decimal power nonlinearities", Journal of Mathematical

Analysis and Applications 114 (2), 423โ€“425, (1986).

[26] H. Aminikhah, "Approximate analytical solution for quadratic Riccati

differential equation", Iranian Journal of Numerical Analysis and

Optimization 3 (2), 21โ€“31, (2013).

[27] H. Bateman, "Some Recent Researches on the Motion of Fluids",

Monthly Weather Review 43, 163โ€“170, (1915).

[28] H. Temimi, A. R. Ansare, "A new iterative technique for solving

nonlinear second order multi-point boundary value problems", Applied

Mathematics and Computation 218 (4), 1457โ€“1466, (2011).

[29] H. Temimi, A. R. Ansari, "A semi โ€“ analytical iterative technique for

solving nonlinear problems", Computers and Mathematics with

Applications 61, 203โ€“210, (2011).

[30] H. Zhu, H. Shu, M. Ding, "Numerical solutions of two-dimensional

Burgersโ€™ equations by discrete Adomian decomposition method",

Computers and Mathematics with Applications 60 (3), 840โ€“848,

(2010).

[31] I. Lasiecka, A. Tuffaha, "Riccati equations arising in boundary control

of fluid structure interactions", International Journal of Computing

Science and Mathematics 1 (1), 128โ€“146, (2007).

[32] J. Ali, "Analysis and Application of Optimal Homotopy Asymptotic

Method and the Use of Daftardar Jaffery Polynomials", Doctoral

Dissertation, Islamia College Peshawar, Peshawar, (2013).

[33] J. Biazar, H. Ghazvini, "Convergence of the homotopy perturbation

method for partial differential equations", Nonlinear Analysis Real

World Applications 10 (5), 2633โ€“2640, (2009).

[34] J. Cang, Y. Tan, H. Xu, S. J. Liao, "Series solutions of non-linear

Riccati differential equations with fractional order", Chaos, Solitons

and Fractals 40 (1), 1โ€“9, (2009).

Page 146: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

References

125

[35] J. Duan, R. Rach, A. M. Wazwaz," Steady-state concentrations of

carbon dioxide absorbed into phenyl glycidyl ether solutions by the

Adomian decomposition method", Math Chem 53, 1054โ€“1067, (2015).

[36] J. D. Cole, "On a quasilinear parabolic equations occurring in

aerodynamics", Quarterly of Applied Mathematics 9, 225โ€“236, (1951).

[37] J. D. Logan, "An Introduction to Nonlinear Partial Differential

Equations", Wiley-Interscience, New York, (1994).

[38] J. H. He, "Variational iteration method for autonomous ordinary

differential systems", Applied Mathematics and Computation 114 (2-3),

115โ€“123, (2000).

[39] J. H. He, "Variational iteration method-a kind of nonlinear analytical

technique: some examples", International Journal of Non-

linear Mechanics 34 (4), 699โ€“708, (1999).

[40] J. H. He, "Variational iteration method for delay differential equations",

Communications in Nonlinear Science and Numerical Simulation 2 (4),

235โ€“236, (1997).

[41] J. H. He, "Variational iteration method-Some recent results and new

interpretations", Journal of Computational and Applied Mathematics

207, 3โ€“17, (2007).

[42] J. H. He, "Homotopy perturbation technique", Computer Methods in

Applied Mechanics and Engineering 178 (3-4), 257โ€“262, (1999).

[43] J. H. He, X. H. Wu, "Construction of solitary solution and compacton-

like solution by variational iteration method", Chaos Solitons Fractals

29 (1), 108โ€“113, (2006).

[44] J. K. Zhou, "Differential transform and its application for electrical

circuits". Wuhan: Huazhong University Press, [in Chinese], (1986).

[45] J. M. Burgers, "A mathematical model illustrating the theory of

turbulence", Advances in Applied Mechanics 1, 171โ€“199, (1948).

[46] J. R. Ockendon, A. B. Taylor, "The dynamics of a current collection

systemfor an electric locomotive", Proc. R. Soc. Lond, Ser.A 322, 447โ€“

468 (1971).

[47] K. R. Desai, V. H. Pradhan, "Solution of Burgersโ€™ Equation and

Coupled Burgersโ€™ Equations by Homotopy Perturbation Method",

Page 147: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

References

126

International Journal of Engineering Research and Applications

(IJERA) 2, 2033โ€“2040, (2012).

[48] L. Debtnath, "Nonlinear Partial Differential Equations for Scientist and

Engineers", Birkhauser, Boston, (1997).

[49] L. Fox, D. F. Mayers, J. A. Ockendon, A. B. Tayler, "On a functional

differential equation", Journal of Mathematical Analysisand

Applications 8, 271โ€“307, (1971).

[50] M. A. Abdou, A. A. Soliman, "Variational iteration method for solving

Burgersโ€™ and coupled Burgersโ€™equations", Journal of Computational

and Applied Mathematics 181, 245โ€“251, (2005).

[51] M. A. AL-Jawary, S. G. Al-Razaq, "A semi analytical iterative

technique for solving Duffing equations", International Journal of Pure

and Applied Mathematics 108 (4), 871โ€“885, (2016).

[52] M. A. AL-Jawary, R. K. Raham, "A semi-analytical iterative technique

for solving chemistry problems", Journal of King Saud University, (In

press), (2016).

[53] M. A. AL-Jawary, "A semi-analytical iterative method for solving

nonlinear thin film flow problems", Chaos, Solitons and Fractals 99,

52โ€“56, (2017).

[54] M. A. AL-Jawary, G. H. Radhi, "The variational iteration method for

calculating carbon dioxide absorbed into phenyl glycidyl ether", IOSR

Journal of Mathematics 1, 99โ€“105, (2015).

[55] M. Ahmadian, M. Mojahedi, H. Moeenfard, "Free vibration analysis of

a nonlinear beam using homotopy and modified lindstedt-poincare

methods", Journal of Solid Mechanics 1 (1), 29โ€“36, (2009).

[56] M. Basto, V. Semiao, F. Calheiros, "Dynamics and synchronization of

numerical solutions of the Burgersโ€™ equation", Journal of

Computational and Applied Mathematics 231 (2), 793โ€“806, (2009).

[57] M. C. Joshi, R. K. Bose, "Some Topics in Nonlinear Functional

Analysis", Wiley Eastern Limited, New Delhi, (1985).

[58] M. D. Buhmann, A. Iserles, "Stability of the discretized pantograph

differential equation", Journal of Mathematics and Computing 60, 575โ€“

589, (1993).

Page 148: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

References

127

[59] M. Glsu, M. Sezer, "On the solution of the Riccati equation by the

Taylor matrix method", Applied Mathematics and Computation 176

(2), 414โ€“421, (2006).

[60] M. Khan, "A novel solution technique for two dimensional Burgersโ€™

equation", Alexandria Engineering Journal 53, 485โ€“490, (2014).

[61] M. M. Rashidi, E. Erfani, "New analytical method for solving Burgersโ€™

and nonlinear heat transfer equations and comparison with HAM",

Computer Physics Communications 180 (9), 1539โ€“1544, (2009).

[62] M. Sezer, A. Akyยจuz-Dasยธcฤฑoห˜glu, "A Taylor method for numerical

solution of generalized pantograph equations with linear functional

Argument", Journal of Computational and Applied Mathematics 200

217โ€“225, (2007).

[63] M. SH. Chowdhury, I. Hashim, O. Abdulaziz, "Comparison of

homotopy analysis method and homotopy-perturbation method for

purely nonlinear fin-type problems", Communications in Nonlinear

Science and Numerical Simulation 14 (2), 371โ€“378, (2009).

[64] N. A. Khan, A. Ara, N. A. Khan, "Fractional order Riccati differential

equation analytical approximation and numerical results", Advances in

Difference Equations, Accepted article 185 (1), 1โ€“16, (2013).

[65] R. E. Bellman, R. E. Kalaba, "Quasilinearisation and nonlinear

boundary-value problems", Elsevier, New York 3, (1965).

[66] R. Nawaz, H. Ullah, S. Islam, M. Idrees, "Application of Optimal

Homotopy Asymptotic Method to Burgersโ€™ Equations", Journal of

Applied Mathematics 2013, (2013).

[67] R. V. Kakde, S. S. Biradar, S. S. Hiremath, " Solution of differential and

integral equations using fixed point theory ", International Journal of

Advanced Research in Computer Engineering and Technology

(IJARCET) 3 (5), 1656โ€“1659, (2014).

[68] S. Abbasbandy, "Homotopy perturbation method for quadratic Riccati

differential equation and comparison with Adomian's decomposition

method", Applied Mathematics and Computation 172 (1), 485โ€“490,

(2006).

Page 149: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

References

128

[69] S. Banach, "Sur les opรฉrations dans les ensembles abstraits et leur

application aux equations integrals", Fundamenta Mathematicae 3,

133โ€“181, (1922).

[70] S. J. Liao, A. T. Chwang, "Application of homotopy analysis method in

nonlinear oscillations", Journal of Applied Mechanics 65 (4), 914โ€“

922, (1998).

[71] S. J. Liao, "Beyond perturbation: introduction to the homotopy analysis

method", Boca Raton: Chapman and Hall /CRC Press, (2003).

[72] S. M. El-Sayed, D. Kaya, "On the numerical solution of the system of

two-dimensional Burgersโ€™ equations by the decomposition method",

Applied Mathematics and Computation 158, 101โ€“109, (2004).

[73] S. Yuzbasi, M. Sezer, "An exponential approximation for solutions of

generalized pantograph-delay differential equations", Applied

Mathematical Modeling 37 (22), 9160โ€“9173, (2013).

[74] T. Allahviranloo, S. Sh. Behzadi, "Application of Iterative Methods for

Solving General Riccati Equation", International Journal of Industrial

Mathematics (IJIM) 4 (4), 389โ€“404, (2012).

[75] V. Daftardar-Gejji, S. Bhalekar, "Solving nonlinear functional equation

using Banach contraction principle" Far East Journal of Applied

Mathematics 34 (3), 303โ€“314, (2009).

[76] V. K. Srivastava , N. Mishra, S. Kumar, B. K. Singh , M. K. Awasthi ,

"Reduced differential transform method for solving (1+n)-Dimensional

Burgersโ€™ equation", Egyptian Journal of Basic and Applied Sciences 1

(2), 115-119, (2014).

[77] W. M. Moslem, R. Sabry, "Zakharov-Kuznetsov- Burgersโ€™ equation for

dust ion acoustic waves", Chaos Solitons Fractals 36 (3), 628โ€“634,

(2008).

[78] Y. Keskin, A. Kurnaz, M. E. Kiris, G. Oturanc, "Approximate solutions

of generalized pantograph equations by the differential transform

method", International Journal of Nonlinear Sciences and Numerical

Simulation 8 (2), 159-164, (2007).

[79] Y. Li, L. Hu, L "Solving fractional Riccati differential equations using

Haar Wavelet", Third International Conference on Information and

Computing 5, 314โ€“317, (2010).

Page 150: ihcoedu.uobaghdad.edu.iq...Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Education for Pure Science / Ibn Al-Haitham Department

References

129

[80] Y. L. Duan, R. X. Liu, "Lattice Boltzmann model for two-dimensional

unsteady Burgersโ€™ equation", Journal of Computational and Applied

Mathematics 206 (1), 432-439, (2007).

[81] Y. Yang, Y. Huang, "Spectral Collocation Methods for Fractional

Pantograph Delay Integro differential Equations", Advances in

Mathematical Physics 2013, 14, (2013).

[82] Z. Odibat, S. Momani, "Modified homotopy perturbation method

application to quadratic Riccati differential equation of fractional

order", Chaos, Solitons and Fractals 36 (1), 167โ€“174, (2008).

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APPENDICES

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Appendices

130

Appendix A: Code of Mathematica for chapter one (the ADM)

**************************************************************

Code of example (1.1)

**************************************************************

(* v'=-v2 +1, v(0)=0 *)

tt=AbsoluteTime[];

zz=SessionTime[];

v0=x;

v1= -Integrate[v0^2/. xt,{t,0,x}]

-x3/3

v2= -Integrate[2v0*v1/. xt,{t,0,x}]

2x5/15

v3= -Integrate[2v0*v2+v1^2 /. xt,{t,0,x}]

-17x7/315

v4= -Integrate[2v0*v3+2v1*v2 /. xt,{t,0,x}];

v5= -Integrate[2v0*v4+2v1*v3+v2^2 /. xt,{t,0,x}];

v6= -Integrate[2v0*v5+2v2*v3+2v1*v4 /. xt,{t,0,x}];

v=v0+v1+v2+v3+v4+v5+v6

x-x3/3+2x5/15-17x7/315+62x9/2835-1382x11/155925+ 21844x13/6081075

r1=Abs[D[v0+v1,{x,1}]+(v0+v1)^2-1];

Plot[r1,{x,0,1}]

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Appendices

131

r2=Abs[D[v0+v1+v2,{x,1}]+(v0+v1+v2)^2-1];

Plot[r2,{x,0,1}]

r3=Abs[D[v0+v1+v2+v3,{x,1}]+(v0+v1+v2+v3)^2-1];

Plot[r3,{x,0,1}]

r4=Abs[D[v0+v1+v2+v3+v4,{x,1}]+(v0+v1+v2+v3+v4)^2-1];

Plot[r4,{x,0,1}]

0.2 0.4 0.6 0.8 1.0

0.1

0.2

0.3

0.4

0.5

0.2 0.4 0.6 0.8 1.0

0.05

0.10

0.15

0.20

0.2 0.4 0.6 0.8 1.0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

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Appendices

132

r5=Abs[D[v0+v1+v2+v3+v4+v5,{x,1}]+(v0+v1+v2+v3+v4+v5)^2-1];

Plot[r5,{x,0,1}]

r6=Abs[D[v0+v1+v2+v3+v4+v5+v6,{x,1}]+(v0+v1+v2+v3+v4+v5+v6)^2-

1];

Plot[r6,{x,0,1}]

x ={0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1};

r1;r2;r3;r4;r5;r6;

Y1=Max[r1]

0.2 0.4 0.6 0.8 1.0

0.005

0.010

0.015

0.020

0.025

0.030

0.2 0.4 0.6 0.8 1.0

0.002

0.004

0.006

0.008

0.2 0.4 0.6 0.8 1.0

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

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Appendices

133

0.0000665556

Y2=Max[r2]

3.76891ร—10-7

Y3=Max[r3]

1.96289ร—10-9

Y4=Max[r4]

9.72067ร—10-12

Y5=Max[r5]

4.65513ร—10-14

Y6=Max[r6]

2.15106ร—10-16

Y={Y1,Y2,Y3,Y4,Y5,Y6};

n={1,2,3,4,5,6};

ListLog-

Plot[{{1,Y1},{2,Y2},{3,Y3},{4,Y4},{5,Y5},{6,Y6}},JoinedTrue,PlotRan

geAll,FrameTrue,

AesTrue,FrameLabel{Row[{Style["n",FontSlantItalic]}],Row[{Style[

"MERn",FontSlantItalic]}]},PlotMarkers{Automatic,15}]

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Appendices

134

Appendix B: Code of Mathematica for chapter one (the VIM)

**************************************************************

Code of example (1.7)

**************************************************************

(* D[v,{t,1}]+v*D[v,{x,1}]+ v*D[v,{y,1}]= k (D[v,{x,2}]+D[v,{y,2}]),

v(x,y,0)= sin(2ฯ€x)cos(2ฯ€y) *)

tt=AbsoluteTime[];

zz=SessionTime[];

v0= sin(2ฯ€x)cos(2ฯ€y);

v1=v0-Integrate[(D[v0,{t,1}]+v0*D[v0,{x,1}]+ v0*D[v0,{y,1}]-k

(D[v0,{x,2}]+D[v0,{y,2}]),{t,0,t}];

v2=v1-Integrate[(D[v1,{t,1}]+v1*D[v1,{x,1}]+ v1*D[v1,{y,1}]-k

(D[v1,{x,2}]+D[v1,{y,2}]),{t,0,t}];

v3=v2-Integrate[(D[v2,{t,1}]+v2*D[v2,{x,1}]+ v2*D[v2,{y,1}]-k

(D[v2,{x,2}]+D[v2,{y,2}]),{t,0,t}];

v4=v3-Integrate[(D[v3,{t,1}]+v3*D[v3,{x,1}]+ v3*D[v3,{y,1}]-k

(D[v3,{x,2}]+D[v3,{y,2}]),{t,0,t}];

r1=Abs[D[v1,{t,1}]+v1*D[v1,{x,1}]+ v1*D[v1,{y,1}]-k

(D[v1,{x,2}]+D[v1,{y,2})];

r2=Abs[D[v2,{t,1}]+v2*D[v2,{x,1}]+ v2*D[v2,{y,1}]-k

(D[v2,{x,2}]+D[v2,{y,2})];

r3=Abs[D[v3,{t,1}]+v3*D[v3,{x,1}]+ v3*D[v3,{y,1}]-k

(D[v3,{x,2}]+D[v3,{y,2})];

r4=Abs[D[v4,{t,1}]+v4*D[v4,{x,1}]+ v4*D[v4,{y,1}]-k

(D[v4,{x,2}]+D[v4,{y,2})];

k =0.1;

t =0.0001;

x ={0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1};

y ={0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1};

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Appendices

135

r1;r2;r3;r4;

Y1=Max[r1]

0.0161705

Y2=Max[r2]

0.0000252036

Y3=Max[r3]

3.56783ร—10-8

Y4=Max[r4]

4.53593ร—10-11

Y={Y1,Y2,Y3,Y4};

n={1,2,3,4};

ListLog-

Plot[{{1,Y1},{2,Y2},{3,Y3},{4,Y4}},JoinedTrue,PlotRangeAll,Frame

True,AesTrue,FrameLabel{Row[{Style["n",FontSlantItalic]}],Row[

{Style["MERn",FontSlantItalic]}]},PlotMarkers{Automatic,15}]

1.0 1.5 2.0 2.5 3.0 3.5 4.010 11

10 8

10 5

10 2

n

ME

Rn

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Appendices

136

Appendix C: Code of Mathematica for chapter two (the TAM)

**************************************************************

Code of example (2.4)

**************************************************************

(* v''''=v2-x10+4x9-4x8-4x7+8x6-4x4+120x-48, v(0)= v'(0)=0, v(1)= v'(1)=1 *)

(* L(v)= v'''', N(v)= v2 and f(x)=-(-x10+4x9-4x8-4x7+8x6-4x4+120x-48) *)

tt=AbsoluteTime[];

zz=SessionTime[];

v01[x_]=v0[x]/.First@DSolve[{v0''''[x] -x10+4x9-4x8-4x7+8x6-4x4+120x-48,

v0[0]0, v0'[0]0, v0[1]=1, v0'[1]=1}, v0, x];

Expand[v01[x]]

718561x2/360360+4019x3/540540-2x4+x5-x8/420+x10/360-x11/1980-

x12/2970+x13/4290-x14/24024

v11[x_]=v1[x]/.First@DSolve[{v1''''[x] (v01[x])^2 -x10+4x9-4x8-4x7+8x6-

4x4+120x-48, v1[0]0, v1'[0]0, v1[1]=1, v1'[1]=1}, v1, x];

v22[x_]=v2[x]/.First@DSolve[{v2''''[x] (v11[x])^2 -x10+4x9-4x8-4x7+8x6-

4x4+120x-48, v2[0]0, v2'[0]0, v2[1]=1, v2'[1]=1}, v2, x];

v33[x_]=v3[x]/.First@DSolve[{v3''''[x] (v22[x])^2 -x10+4x9-4x8-4x7+8x6-

4x4+120x-48, v3[0]0, v3'[0]0, v3[1]=1, v3'[1]=1}, v3, x];

v44[x_]=v4[x]/.First@DSolve[{v4''''[x] (v33[x])^2 -x10+4x9-4x8-4x7+8x6-

4x4+120x-48, v3[0]0, v4'[0]0, v4[1]=1, v4'[1]=1}, v4, x];

v55[x_]=v5[x]/.First@DSolve[{v5''''[x] (v44[x])^2 -x10+4x9-4x8-4x7+8x6-

4x4+120x-48, v5[0]0, v5'[0]0, v5[1]=1, v5'[1]=1}, v5, x];

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Appendices

137

v66[x_]=v6[x]/.First@DSolve[{v6''''[x] (v55[x])^2 -x10+4x9-4x8-4x7+8x6-

4x4+120x-48, v6[0]0, v6'[0]0, v6[1]=1, v6'[1]=1}, v6, x];

x={0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1};

v=x5-2x4+2x2;

r1=Abs[v-v11[x]]

{ 0, 1.02627ร—10-7, 3.47659ร—10-7, 6.41401ร—10-7, 8.93924ร—10-7, 1.02777ร—10-6,

9.93141ร—10-7, 7.86445ร—10-7, 4.64662ร—10-7, 1.471ร—10-7, 2.22045ร—10-16 }

r2=Abs[v-v22[x]];

r3=Abs[v-v33[x]];

r4=Abs[v-v44[x]];

r5=Abs[v-v55[x]];

r6=Abs[v-v66[x]];

Appendix D: Code of Mathematica for chapter three (the BCM)

**************************************************************

Code of example (3.4)

**************************************************************

(* v''=3/4*v+v(x/2)-x2+2, v(0)=0, v'(0)=0 *)

tt=AbsoluteTime[];

zz=SessionTime[];

v0= x2-x4/12;

a0=v0 /. xx/2;

v1= v0+Integrate[(x-t)*((3/4*v0+a0)/. xt),{t,0,x}]

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Appendices

138

x2-13x6/5760

a1=v1 /. xx/2;

v2= v0+Integrate[(x-t)*((3/4*v1+a1)/. xt),{t,0,x}]

x2-91x8/2949120

a2=v2 /. xx/2;

v3= v0+Integrate[(x-t)*((3/4*v2+a2)/. xt),{t,0,x}]

x2-17563x10/67947724800

a3=v3 /. xx/2;

v4= v0+Integrate[(x-t)*((3/4*v3+a3)/. xt),{t,0,x}]

x2-13505947x12/9184358065766400

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ุงู„ู…ุณุชุฎู„ุต

ุงู„ุญู„ูˆู„ ุฅู„ูŠุฌุงุฏ ุงู„ู‡ุฏู ุงู„ุฑุฆูŠุณูŠ ู…ู† ู‡ุฐู‡ ุงู„ุฑุณุงู„ุฉ ู‡ูˆ ุงุณุชุฎุฏุงู… ุงุซู†ุชูŠู† ู…ู† ุทุฑุงุฆู‚ ุชูƒุฑุงุฑูŠุฉ ุดุจู‡ ุชุญู„ูŠู„ูŠุฉ

ุงู„ุชุญู„ูŠู„ูŠุฉ ู„ุจุนุถ ุงู„ู…ุณุงุฆู„ ุงู„ู…ู‡ู…ุฉ ููŠ ุงู„ููŠุฒูŠุงุก ูˆุงู„ู‡ู†ุฏุณุฉ.

ู…ู† ู‚ุจู„ ุงู„ุชู…ูŠู…ูŠ ูˆุงุฃู„ู†ุตุงุฑูŠ ุฃุงู„ ุงู„ุฐูŠ ุงู‚ุชุฑุญู‡ุงุฃู„ูˆู„ู‰ ุฉ ุงู„ุชูƒุฑุงุฑูŠ ู„ุทุฑูŠู‚ุฉุง ุงุณุชุฎุฏุงู… ู‡ูˆ ุงุฃู„ูˆู„ ุงู„ู‡ุฏู

ู„ุฐุฑุงุน ุงู„ู…ุชุฐุจุฐุจ. ุงุชุดูˆู‡ ูˆ ุจุงู†ุชูˆุบุฑุงูุŒ ุฑูŠูƒุงุชูŠุŒ ู„ู…ุนุงุฏุงู„ุชุงู„ุญู„ูˆู„ ุงู„ุชุญู„ูŠู„ูŠุฉ ุฅู„ูŠุฌุงุฏ (TAM) ูˆู‡ูŠ ุงู„ู€

( ุนู„ู‰ ู…ุนุงุฏุงู„ุช ูˆุงู†ุธู…ุฉ ู…ุนุงุฏุงู„ุช ุจุฑุฌุฑุฒ ุงู„ุบูŠุฑ ุฎุทูŠุฉ ุงุฃู„ุญุงุฏูŠุฉ ุงู„ุจุนุฏ TAMู‚ุฏ ุชู… ุชุทุจูŠู‚ ุงู„ู€ ) ุงูŠุถุงุŒ

( ู‚ุฏ ุชู… TAMูˆุงู„ุซู†ุงุฆูŠุฉ ุงุงู„ุจุนุงุฏ ูˆุงู„ุซุงู„ุซูŠุฉ ุงุงู„ุจุนุงุฏ ู„ู„ุญุตูˆู„ ุนู„ู‰ ุงู„ุญู„ูˆู„ ุงู„ุชุญู„ูŠู„ูŠุฉ ู„ูƒู„ ู…ู†ู‡ุง. ุงู„ุชู‚ุงุฑุจ ู„ู„ู€ )

ุงู„ุชุญู‚ู‚ ู…ู†ู‡ ูˆุฅุซุจุงุชู‡ ุจู†ุฌุงุญ ู„ุชู„ูƒ ุงู„ู…ุณุงุฆู„.

ูŠุณู‡ู„ ุงู„ุชูŠ( BCMุงู†ู‚ุจุงุถ ุจู†ุงุฎ )ุทุฑูŠู‚ุฉ ุฃุณุงุณ ุนู„ู‰ ุชูƒุฑุงุฑูŠุฉ ุชู‚ู†ูŠุฉ ุงุณุชุฎุฏุงู… ู‡ูˆ ุงู„ุซุงู†ูŠ ูˆุงู„ู‡ุฏู

( ู„ุญู„ ู†ูุณ ุงู„ู…ุณุงุฆู„ BCM. ุชู… ุงุณุชุฎุฏุงู… ุงู„ู€ )ุงู„ุฎุทูŠุฉ ุบูŠุฑ ุงู„ู…ุตุทู„ุญุงุช ู…ุน ุงู„ุชุนุงู…ู„ ููŠ ุชุทุจูŠู‚ู‡ุง

( TAMุจูŠู† ุงู„ู€ )ุงู„ู…ู‚ุงุฑู†ุงุช ู…ู† ุงู„ุนุฏูŠุฏ ู‚ุฏู…ู†ุง ุฐู„ูƒุŒ ุฅู„ู‰ ูˆุจุงุฅู„ุถุงูุฉุงู„ููŠุฒูŠุงุฆูŠุฉ ูˆุงู„ู‡ู†ุฏุณูŠุฉ ุงู„ู…ุฐูƒูˆุฑุฉ ุฃุนุงู„ู‡.

( ู…ุน ุจุนุถ ADM) ุฃุฏูˆู…ูŠุงู† ุชููƒูŠูƒุทุฑูŠู‚ุฉ ( ูˆVIM) ุทุฑูŠู‚ุฉ ุงู„ุชุบุงูŠุฑูŠุฉ ุงู„ุชูƒุฑุงุฑูŠุฉ( ูˆุงู„BCMูˆุงู„ู€ )

( ูˆุงู„ู€ TAMุนุงู„ูŠุฉ. ุงู„ู€ )ูˆุชู…ุชู„ูƒ ุฏู‚ุฉ ูƒูุคุฉ ุงู„ู…ู‚ุฏู…ุฉุงู„ุทุฑุงุฆู‚ .ุงุงู„ุณุชู†ุชุงุฌุงุช ูˆุงุฃู„ุนู…ุงู„ ุงู„ู…ุณุชู‚ุจู„ูŠุฉ

(BCM ุงู„ ุชุชุทู„ุจุงู† ุงูŠุฉ ุงูุชุฑุงุถุงุช ู…ู‚ูŠุฏุฉ ููŠ ุงู„ุญุงู„ุฉ )ูƒุงู„ ุงู„ุทุฑูŠู‚ุชูŠู† ุงู„ ุฐู„ูƒุŒ. ุจุงุฅู„ุถุงูุฉ ุงู„ู‰ ุบูŠุฑ ุฎุทูŠุฉ

( ุฃูˆ VIM( ุฃูˆุงู„ู€ )ADMููŠ ุงู„ู€ )ุงู„ุญุงู„ ู‡ูˆุชุนุชู…ุฏุงู† ุนู„ู‰ ุงุณุชุฎุฏุงู… ุฃูŠ ุงูุชุฑุงุถุงุช ู…ู‚ูŠุฏุฉ ุงุถุงููŠุฉ ูƒู…ุง

ุฃูŠุฉ ุทุฑุงุฆู‚ ุชูƒุฑุงุฑูŠุฉ ุฃุฎุฑู‰.

.10 ยฎู…ุงุซูŠู…ุงุชูŠูƒุงุงู„ุจุฑู†ุงู…ุฌ ุงู„ู…ุณุชุฎุฏู… ู„ู„ุญุณุงุจุงุช ููŠ ู‡ุฐู‡ ุงู„ุฑุณุงู„ุฉ ุงู„ู…ู‚ุฏู…ุฉ ู‡ูˆ

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ุฌู…ู‡ูˆุฑูŠุฉ ุงู„ุนุฑุงู‚

ูˆุฒุงุฑุฉ ุงู„ุชุนู„ูŠู… ุงู„ุนุงู„ูŠ ูˆุงู„ุจุญุซ ุงู„ุนู„ู…ูŠ

ุฌุงู…ุนุฉ ุจุบุฏุงุฏ

ูƒู„ูŠุฉ ุงู„ุชุฑุจูŠุฉ ู„ู„ุนู„ูˆู… ุงู„ุตุฑูุฉ / ุงุจู† ุงู„ู‡ูŠุซู…

ู‚ุณู… ุงู„ุฑูŠุงุถูŠุงุช

ุฉ ู„ู„ู…ุนุงุฏุงู„ุช ูŠุงุฆู‚ ุชูƒุฑุงุฑูŠุฉ ุดุจู‡ ุชุญู„ูŠู„ุทุฑ

ุฎุทูŠุฉุงู„ุบูŠุฑ ุงู„ุชูุงุถู„ูŠุฉ ุงู„ุฎุทูŠุฉ ูˆ

ุฑุณุงู„ุฉ

ุŒ ุฌุงู…ุนุฉ ุจุบุฏุงุฏ ุงุจู† ุงู„ู‡ูŠุซู…/ ู…ู‚ุฏู…ุฉ ุฅู„ู‰ ูƒู„ูŠุฉ ุงู„ุชุฑุจูŠุฉ ู„ู„ุนู„ูˆู… ุงู„ุตุฑูุฉ

ููŠ ุงู„ุฑูŠุงุถูŠุงุชู…ุงุฌุณุชูŠุฑ ุนู„ูˆู… ูƒุฌุฒุก ู…ู† ู…ุชุทู„ุจุงุช ู†ูŠู„ ุฏุฑุฌุฉ

ู…ู† ู‚ุจู„

ู…ุตุทูู‰ ู…ุญู…ูˆุฏ ุนุฒูŠุฒ ุจุฅุดุฑุงู

ู…ุฌูŠุฏ ุฃุญู…ุฏ ูˆู„ูŠ .ุฏ. ู…. ุฃ

ู… 2017 ฺพ 1438