Java

TOPIC 10 – MATH FUNCTIONS

LESSON WORK

QUESTION 1

Answer the following questions.

a) What does API stand for?

b) What is the URL for Java’s API? (Use Google to find it.)

c) In the Math class, there is a max function. What does it do?

d) Which Math class function can be used to round a number up?

e) Which Math class function can be used to round a number down?

f) What is the absolute value of a number? There is a function for this.

g) What is a function prototype (also known as a method prototype)?

Save your work inside the file Question01.txt in the topic10 folder.

QUESTION 2 (SELF-CHECK)

Use Java’s Math function to write the following statements inside a Java program:

a) a = squareroot of 101

b) b = 5⁵

c) c = a² + b²

d) d = rounded value of a

e) e = integer value of a

f) f = random decimal number between 0 and 1

g) g = cube root of 81

h)

i) i = 2^{(d + 3)}

j) j = 100^0.5 * 2⁵

k) k = absolute value of -4

To verify the answers, you could make your program output to screen the value of each variable.

Save your program in MathTest.java in the topic10 folder.

Check your answers here.

QUESTION 3

What value will the variable get?

a) int a = Math.abs(-25);

b) double b = Math.ceil(7.9);

c) double c = Math.pow(2,4);

d) int d = Math.min(-3, 2);

e) double e = Math.pow(Math.min(2,4), Math.max(1,2));

f) double f = 28 / 7 * Math.abs(4);

g) double g = Math.pow(Math.pow(2,2),3);

h) double h = Math.min(Math.pow(2,3),Math.pow(2,Math.max(1,2)));

i) double i = Math.PI * 2;

j) double j = Math.abs(Math.min(-3, 2));

Save your work inside the file Question03.txt in the topic10 folder.

QUESTION 4

Inside a program called Randomness.java, do the following:

a) Write a statement that generates a random number between 0 and 1. Output the number to screen. Test your program.

b) Write another statement that generates a random number between 0 and 10. Output the number to screen. Test your program.

c) Write another statement that generates a random whole number between 0 and 10. Output the number to screen. Test your program.

d) Write another statement that generates a random whole number between 5 and 15. Output the number to screen. Test your program.

In the end, your program should be generating 4 random numbers each time that it is ran.

Save your program insde the topic10 folder.

QUESTION 5

Write a program that asks the user to input two different numbers. The program simply outputs the largest number of the two. Look up the max function.

Save your work inside a Largest.java file inside the topic10 folder.