In this program we are going to practice using the Math class by computing some important values on the unit circle. Using the angles 0, PI/2, and PI, print out the angle, the cosine of the angle, and the sine of the angle.

The program in Java is as follows:

import java.lang.Math;

public class Trig{

public static void main(String args[]){

for(double angle = 0; angle <= Math.PI; angle += Math.PI / 2){

double cosX = Math.round(Math.cos(angle)*100.0)/100.0;

double sinX = Math.round(Math.sin(angle)*100.0)/100.0;

System.out.println((Math.round(angle*100)/100.0)+" --> "+cosX +" --> "+ sinX);

}}}

Explanation:

This line imports the math library into the program

import java.lang.Math;

This line defines a class

public class Trig{

This line defines the main method

public static void main(String args[]){

This line is an iteration that iterates from 0, through Math.PI using Math.PI/2 as an interval

for(double angle = 0; angle <= Math.PI; angle += Math.PI / 2){

This calculates the cosine of the angle (in radians)

double cosX = Math.round(Math.cos(angle)*100.0)/100.0;

This calculates the sine of the angle (in radians)

double sinX = Math.round(Math.sin(angle)*100.0)/100.0;

This prints the angle in radians, the cosine and the sine of the angle

System.out.println((Math.round(angle*100)/100.0)+" --> "+cosX +" --> "+ sinX);

}}}