x2 t01 09 geometrical representation of complex numbers

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Geometrical Representation of Complex Numbers

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Page 1: X2 T01 09 geometrical representation of complex numbers

Geometrical Representation of Complex Numbers

Page 2: X2 T01 09 geometrical representation of complex numbers

Geometrical Representation of Complex Numbers

Complex numbers can be represented on the Argand Diagram as vectors.

Page 3: X2 T01 09 geometrical representation of complex numbers

Geometrical Representation of Complex Numbers

Complex numbers can be represented on the Argand Diagram as vectors.y

x

Page 4: X2 T01 09 geometrical representation of complex numbers

Geometrical Representation of Complex Numbers

Complex numbers can be represented on the Argand Diagram as vectors.y

x

iyxz

Page 5: X2 T01 09 geometrical representation of complex numbers

Geometrical Representation of Complex Numbers

Complex numbers can be represented on the Argand Diagram as vectors.y

x

iyxz

Page 6: X2 T01 09 geometrical representation of complex numbers

Geometrical Representation of Complex Numbers

Complex numbers can be represented on the Argand Diagram as vectors.y

x

iyxz

The advantage of using vectors is that they can be moved around the Argand Diagram

Page 7: X2 T01 09 geometrical representation of complex numbers

Geometrical Representation of Complex Numbers

Complex numbers can be represented on the Argand Diagram as vectors.y

x

iyxz

The advantage of using vectors is that they can be moved around the Argand Diagram

Page 8: X2 T01 09 geometrical representation of complex numbers

Geometrical Representation of Complex Numbers

Complex numbers can be represented on the Argand Diagram as vectors.y

x

iyxz

The advantage of using vectors is that they can be moved around the Argand DiagramNo matter where the vector is placed its length (modulus) and the angle made with the x axis (argument) is constant

Page 9: X2 T01 09 geometrical representation of complex numbers

Geometrical Representation of Complex Numbers

Complex numbers can be represented on the Argand Diagram as vectors.y

x

iyxz

The advantage of using vectors is that they can be moved around the Argand DiagramNo matter where the vector is placed its length (modulus) and the angle made with the x axis (argument) is constant

A vector always

represents

HEAD minus TAIL

Page 10: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

Page 11: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

Page 12: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

Page 13: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

Page 14: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

Page 15: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

21 zz

Page 16: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

21 zz

Page 17: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

21 zz

To subtract two complex numbers, place the vectors “head to head” (or add the negative vector)

Page 18: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

21 zz

To subtract two complex numbers, place the vectors “head to head” (or add the negative vector)

21 zz

Page 19: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

21 zz

To subtract two complex numbers, place the vectors “head to head” (or add the negative vector)

21 zz

Page 20: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

21 zz

To subtract two complex numbers, place the vectors “head to head” (or add the negative vector)

21 zz 2121 and diagonals; twohas vectors

addingby formed ramparallelog the:

zzzz

NOTE

Page 21: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

21 zz

To subtract two complex numbers, place the vectors “head to head” (or add the negative vector)

21 zz 2121 and diagonals; twohas vectors

addingby formed ramparallelog the:

zzzz

NOTE

Page 22: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

21 zz

To subtract two complex numbers, place the vectors “head to head” (or add the negative vector)

21 zz 2121 and diagonals; twohas vectors

addingby formed ramparallelog the:

zzzz

NOTE

Trianglar InequalityIn any triangle a side will be shorter than the sum of the other two sides

Page 23: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

21 zz

To subtract two complex numbers, place the vectors “head to head” (or add the negative vector)

21 zz 2121 and diagonals; twohas vectors

addingby formed ramparallelog the:

zzzz

NOTE

Trianglar InequalityIn any triangle a side will be shorter than the sum of the other two sides

BCABACABC ;In

Page 24: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

21 zz

To subtract two complex numbers, place the vectors “head to head” (or add the negative vector)

21 zz 2121 and diagonals; twohas vectors

addingby formed ramparallelog the:

zzzz

NOTE

Trianglar InequalityIn any triangle a side will be shorter than the sum of the other two sides

BCABACABC ;In (equality occurs when AC is a straight line)

Page 25: X2 T01 09 geometrical representation of complex numbers

Addition / Subtraction

y

x

1z

2z

To add two complex numbers, place the vectors “head to tail”

21 zz

To subtract two complex numbers, place the vectors “head to head” (or add the negative vector)

21 zz 2121 and diagonals; twohas vectors

addingby formed ramparallelog the:

zzzz

NOTE

Trianglar InequalityIn any triangle a side will be shorter than the sum of the other two sides

BCABACABC ;In (equality occurs when AC is a straight line)

2121 zzzz

Page 26: X2 T01 09 geometrical representation of complex numbers

AdditionIf a point A represents and point B represents then point C representing

is such that the points OACB form a parallelogram.

1z2z

21 zz

Page 27: X2 T01 09 geometrical representation of complex numbers

AdditionIf a point A represents and point B represents then point C representing

is such that the points OACB form a parallelogram.

1z2z

21 zz

SubtractionIf a point D represents and point E represents then the points ODEB form a parallelogram.

Note:

1z12 zz

12 zzAB

12arg zz

Page 28: X2 T01 09 geometrical representation of complex numbers

1995..ge y

x

P

O

Q

The diagram shows a complex plane with origin O.The points P and Q represent the complex numbers z and w respectively.Thus the length of PQ is wz wzwzi that Show

Page 29: X2 T01 09 geometrical representation of complex numbers

1995..ge y

x

P

O

Q

The diagram shows a complex plane with origin O.The points P and Q represent the complex numbers z and w respectively.Thus the length of PQ is wz wzwzi that Show

Page 30: X2 T01 09 geometrical representation of complex numbers

1995..ge y

x

P

O

Q

The diagram shows a complex plane with origin O.The points P and Q represent the complex numbers z and w respectively.Thus the length of PQ is wz wzwzi that Show

zOP is oflength The

Page 31: X2 T01 09 geometrical representation of complex numbers

1995..ge y

x

P

O

Q

The diagram shows a complex plane with origin O.The points P and Q represent the complex numbers z and w respectively.Thus the length of PQ is wz wzwzi that Show

zOP is oflength ThewOQ is oflength The

Page 32: X2 T01 09 geometrical representation of complex numbers

1995..ge y

x

P

O

Q

The diagram shows a complex plane with origin O.The points P and Q represent the complex numbers z and w respectively.Thus the length of PQ is wz wzwzi that Show

zOP is oflength ThewOQ is oflength The

wzPQ is oflength The

Page 33: X2 T01 09 geometrical representation of complex numbers

1995..ge y

x

P

O

Q

The diagram shows a complex plane with origin O.The points P and Q represent the complex numbers z and w respectively.Thus the length of PQ is wz wzwzi that Show

zOP is oflength ThewOQ is oflength The

wzPQ is oflength Thewzwz

OPQ

on inequalityr triangulatheUsing

Page 34: X2 T01 09 geometrical representation of complex numbers

1995..ge y

x

P

O

Q

The diagram shows a complex plane with origin O.The points P and Q represent the complex numbers z and w respectively.Thus the length of PQ is wz wzwzi that Show

zOP is oflength ThewOQ is oflength The

wzPQ is oflength Thewzwz

OPQ

on inequalityr triangulatheUsing

(ii) Construct the point R representing z + w, What can be said about thequadrilateral OPRQ?

Page 35: X2 T01 09 geometrical representation of complex numbers

1995..ge y

x

P

O

Q

The diagram shows a complex plane with origin O.The points P and Q represent the complex numbers z and w respectively.Thus the length of PQ is wz wzwzi that Show

zOP is oflength ThewOQ is oflength The

wzPQ is oflength Thewzwz

OPQ

on inequalityr triangulatheUsing

(ii) Construct the point R representing z + w, What can be said about thequadrilateral OPRQ?

R

Page 36: X2 T01 09 geometrical representation of complex numbers

1995..ge y

x

P

O

Q

The diagram shows a complex plane with origin O.The points P and Q represent the complex numbers z and w respectively.Thus the length of PQ is wz wzwzi that Show

zOP is oflength ThewOQ is oflength The

wzPQ is oflength Thewzwz

OPQ

on inequalityr triangulatheUsing

(ii) Construct the point R representing z + w, What can be said about thequadrilateral OPRQ?

R

OPRQ is a parallelogram

Page 37: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

Page 38: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

wzwz

Page 39: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

wzwz i.e. diagonals in OPRQ are =

Page 40: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

wzwz i.e. diagonals in OPRQ are =rectanglea is OPRQ

Page 41: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

wzwz i.e. diagonals in OPRQ are =rectanglea is OPRQ

2argarg

zw

Page 42: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

wzwz i.e. diagonals in OPRQ are =rectanglea is OPRQ

2argarg

zw

2arg

zw

Page 43: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

wzwz i.e. diagonals in OPRQ are =rectanglea is OPRQ

2argarg

zw

2arg

zw imaginarypurely is

zw

Page 44: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

wzwz i.e. diagonals in OPRQ are =rectanglea is OPRQ

2argarg

zw

2arg

zw imaginarypurely is

zw

Multiplication

Page 45: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

wzwz i.e. diagonals in OPRQ are =rectanglea is OPRQ

2argarg

zw

2arg

zw imaginarypurely is

zw

Multiplication

2121 zzzz

Page 46: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

wzwz i.e. diagonals in OPRQ are =rectanglea is OPRQ

2argarg

zw

2arg

zw imaginarypurely is

zw

Multiplication

2121 zzzz 2121 argargarg zzzz

Page 47: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

wzwz i.e. diagonals in OPRQ are =rectanglea is OPRQ

2argarg

zw

2arg

zw imaginarypurely is

zw

Multiplication

2121 zzzz 2121 argargarg zzzz

21212211 cisrrcisrcisr

Page 48: X2 T01 09 geometrical representation of complex numbers

?about said becan what , If zwwzwziii

wzwz i.e. diagonals in OPRQ are =rectanglea is OPRQ

2argarg

zw

2arg

zw imaginarypurely is

zw

Multiplication

2121 zzzz 2121 argargarg zzzz

21212211 cisrrcisrcisr

2

2121

by multiplied islength its and by iseanticlockwrotated isvector the,by multiply weif ..

rzzzei

Page 49: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

Page 50: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note:

Page 51: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

Page 52: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

2by iseanticlockwrotation a is by tion Multiplica i

Page 53: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

REMEMBER: A vector is HEAD minus TAIL

2by iseanticlockwrotation a is by tion Multiplica i

Page 54: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

REMEMBER: A vector is HEAD minus TAILy

x

A

O

C

B

)1(D

2by iseanticlockwrotation a is by tion Multiplica i

Page 55: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

REMEMBER: A vector is HEAD minus TAILy

x

A

O

C

B

)1(D

)1( iC

2by iseanticlockwrotation a is by tion Multiplica i

Page 56: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

REMEMBER: A vector is HEAD minus TAILy

x

A

O

C

B

)1(D

)1( iC( 1) 1B i

2by iseanticlockwrotation a is by tion Multiplica i

Page 57: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

REMEMBER: A vector is HEAD minus TAILy

x

A

O

C

B

)1(D

)1( iC( 1) 1B i

( 1) ( 1)B i

2by iseanticlockwrotation a is by tion Multiplica i

Page 58: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

REMEMBER: A vector is HEAD minus TAILy

x

A

O

C

B

)1(D

)1( iC( 1) 1B i

( 1) ( 1)B i

2by iseanticlockwrotation a is by tion Multiplica i

OR

Page 59: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

REMEMBER: A vector is HEAD minus TAILy

x

A

O

C

B

)1(D

)1( iC( 1) 1B i

( 1) ( 1)B i

2by iseanticlockwrotation a is by tion Multiplica i

OR( 1) ( 1)B i

Page 60: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

REMEMBER: A vector is HEAD minus TAILy

x

A

O

C

B

)1(D

)1( iC( 1) 1B i

( 1) ( 1)B i

2by iseanticlockwrotation a is by tion Multiplica i

OR( 1) ( 1)B i

OR

Page 61: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

REMEMBER: A vector is HEAD minus TAILy

x

A

O

C

B

)1(D

)1( iC( 1) 1B i

( 1) ( 1)B i

2by iseanticlockwrotation a is by tion Multiplica i

OR( 1) ( 1)B i

OR

2 ( 1)4

B cis

Page 62: X2 T01 09 geometrical representation of complex numbers

If we multiply by the vector OA will rotate by an angle of in an anti-clockwise direction. If we multiply by it will also multiply the length of OA by a factor of r

1z cis

rcis

ii 2

sin2

cos Note: 1iz will rotate OA anticlockwise 90 degrees.

REMEMBER: A vector is HEAD minus TAILy

x

A

O

C

B

)1(D

)1( iC( 1) 1B i

( 1) ( 1)B i

2by iseanticlockwrotation a is by tion Multiplica i

OR( 1) ( 1)B i

OR

2 ( 1)4

B cis

1 ( 1)B i

Page 63: X2 T01 09 geometrical representation of complex numbers

2000..ge y

x

A

O

C

In the Argand Diagram, OABC is a rectangle, where OC = 2OA.The vertex A corresponds to the complex number

B

Page 64: X2 T01 09 geometrical representation of complex numbers

2000..ge y

x

A

O

C

In the Argand Diagram, OABC is a rectangle, where OC = 2OA.The vertex A corresponds to the complex number

B

? toscorrespondnumber complex What Ci

Page 65: X2 T01 09 geometrical representation of complex numbers

2000..ge y

x

A

O

C

In the Argand Diagram, OABC is a rectangle, where OC = 2OA.The vertex A corresponds to the complex number

B

? toscorrespondnumber complex What Ci

iC 2

Page 66: X2 T01 09 geometrical representation of complex numbers

2000..ge y

x

A

O

C

In the Argand Diagram, OABC is a rectangle, where OC = 2OA.The vertex A corresponds to the complex number

B

? toscorrespondnumber complex What Ci

iC 2

(ii) What complex number corresponds to the point of intersection D of the diagonals OB and AC?

Page 67: X2 T01 09 geometrical representation of complex numbers

2000..ge y

x

A

O

C

In the Argand Diagram, OABC is a rectangle, where OC = 2OA.The vertex A corresponds to the complex number

B

? toscorrespondnumber complex What Ci

iC 2

(ii) What complex number corresponds to the point of intersection D of the diagonals OB and AC?

iiB21

2

Page 68: X2 T01 09 geometrical representation of complex numbers

2000..ge y

x

A

O

C

In the Argand Diagram, OABC is a rectangle, where OC = 2OA.The vertex A corresponds to the complex number

B

? toscorrespondnumber complex What Ci

iC 2

(ii) What complex number corresponds to the point of intersection D of the diagonals OB and AC?

iiB21

2

diagonals bisect in a rectangle

Page 69: X2 T01 09 geometrical representation of complex numbers

2000..ge y

x

A

O

C

In the Argand Diagram, OABC is a rectangle, where OC = 2OA.The vertex A corresponds to the complex number

B

? toscorrespondnumber complex What Ci

iC 2

(ii) What complex number corresponds to the point of intersection D of the diagonals OB and AC?

iiB21

2

diagonals bisect in a rectangle

iD 2121

Page 70: X2 T01 09 geometrical representation of complex numbers

Examples

Page 71: X2 T01 09 geometrical representation of complex numbers

Examples

31 cisB

Page 72: X2 T01 09 geometrical representation of complex numbers

Examples

31 cisB

iB23

21

Page 73: X2 T01 09 geometrical representation of complex numbers

Examples

31 cisB

iB23

21

iBD

Page 74: X2 T01 09 geometrical representation of complex numbers

Examples

31 cisB

iB23

21

iBD

iD21

23

Page 75: X2 T01 09 geometrical representation of complex numbers

Examples

31 cisB

iB23

21

iBD

iD21

23

DBC

Page 76: X2 T01 09 geometrical representation of complex numbers

Examples

31 cisB

iB23

21

iBD

iD21

23

DBC

iC

231

231

Page 77: X2 T01 09 geometrical representation of complex numbers
Page 78: X2 T01 09 geometrical representation of complex numbers

AOiAPi )(

Page 79: X2 T01 09 geometrical representation of complex numbers

AOiAPi )(

11 0 zizP

Page 80: X2 T01 09 geometrical representation of complex numbers

AOiAPi )(

11 0 zizP

11 izzP

Page 81: X2 T01 09 geometrical representation of complex numbers

AOiAPi )(

11 0 zizP

11 izzP 11 ziP

Page 82: X2 T01 09 geometrical representation of complex numbers

AOiAPi )(

11 0 zizP

11 izzP 11 ziP

BOiBQii )(

Page 83: X2 T01 09 geometrical representation of complex numbers

AOiAPi )(

11 0 zizP

11 izzP 11 ziP

BOiBQii )(iBBQ

Page 84: X2 T01 09 geometrical representation of complex numbers

AOiAPi )(

11 0 zizP

11 izzP 11 ziP

BOiBQii )(iBBQ

21 ziQ

Page 85: X2 T01 09 geometrical representation of complex numbers

AOiAPi )(

11 0 zizP

11 izzP 11 ziP

BOiBQii )(iBBQ

21 ziQ

2QPM

Page 86: X2 T01 09 geometrical representation of complex numbers

AOiAPi )(

11 0 zizP

11 izzP 11 ziP

BOiBQii )(iBBQ

21 ziQ

2QPM

2

11 21 ziziM

Page 87: X2 T01 09 geometrical representation of complex numbers

AOiAPi )(

11 0 zizP

11 izzP 11 ziP

BOiBQii )(iBBQ

21 ziQ

2QPM

2

11 21 ziziM

2

2121 izzzzM

Page 88: X2 T01 09 geometrical representation of complex numbers

Exercise 4K; 1 to 8, 11, 12, 13

Exercise 4L; odd