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Computer Programming K

Donovan

Lab 1: While Loops and For Loops

You are to write a program that will perform the tasks below. For each part, you are told which type of loop to use, either a

while loop or a for loop.

1) Prompt the user to enter a positive integer, n, from the keyboard. Using a while loop, for each integer, x, from 1 to n,

print x, square root of x, x^2, x^3, x^4, and x^5. Print the square root values rounded to four decimal places. Your output

should be in table form with headings above each column.

Sample input/output:

Enter a positive integer:

6

x sqrt(x) x^2 x^3 x^4 x^5

1 1.0000 1 1 1 1

2 1.4142 4 8 16 32

3 1.7321 9 27 81 243

4 2.0000 16 64 256 10245 2.2361 25 125 625 3125

6 2.4495 36 216 1296 7776

2) Prompt the user to enter a positive integer, n, from the keyboard. Using a while loop print all the positive, odd divisors

less than n.

Sample input/output:

Enter a positive integer:

420

1

3

5

7

15

21

35

105

3) Prompt the user to enter two positive integers from the keyboard. Using a while loop print all the powers of the first

number entered that are less than or equal to the second number entered.

Sample input/output:

Enter two positive integers:

4 5000

4 ^ 0 is 1

4 ^ 1 is 4

4 ^ 2 is 16

4 ^ 3 is 64

4 ^ 4 is 256

4 ^ 5 is 1024

4 ^ 6 is 4096

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4) Prompt the user to enter a positive integer, n, from the keyboard. Using a for loop print all the positive, evennon-

divisors less than n.

Sample input/output:

Enter a positive integer:

30

4

812

14

16

18

20

22

24

26

28

5) 100 animals of an endangered species are released into a game preserve. The population growth of the animal pack

can be modeled by the logistic function p(t) = 1000 / (1 + 9e^(-.1656t)) where t is measured in months. Using a

for loop print the animal population for each month from 0 to 18 months. Round the population to one decimal place (yes,

I know you cant have 302.4 animals). Hint: use: double e = Math.E;

Sample input/output:

Month Population

0 100.0

1 115.9

2 134.0

3 154.4

4 177.3

. .

. .

. .

17 649.8

18 686.5

6) Prompt the user to enter the principal amount (the amount invested, a double), the interest rate as a decimal (a

double), the number of times interest is compounded per year (an integer), and the number of years the money will be

invested (an integer). Using a for loop print the balance of the investment for each year the money is invested, rounded

to two decimal places. Use the compound interest formula: b = p( 1 + r/n ) ^ ( nt ) where b is the

balance, p is the principal amount, r is the interest rate as a decimal, n is the number of times

interest is compounded per year, t is the number of years the money has been invested.

Sample input/output:

Enter the principal:

1250.75

Enter the interest rate as a decimal:

.0654

Enter the number of times interest is compounded per year:

12

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Enter the number of years the principal is invested:

8

Year Balance

0 1250.75

1 1335.05

2 1425.02

3 1521.06

4 1623.585 1733.00

6 1849.80

7 1974.47

8 2107.54