Why Sin(30) = -0.9880316240928618 in java

Question

I try to show the value of sin 30 in java (eclipse). But it's not a real value, My code :

public class sin30 {
public static void main(String[] args){

    System.out.println("Sin 30 = "+Math.sin(30));

}}

and show : Showing

should sin 30 is 0.5. what's wrong with my code?

well you probably won't get exactly 0.5 even when using radians due to floating point arithmetic — Reimeus, Apr 08 '16 at 23:36

score 9 · Answer 1 · answered Apr 08 '16 at 23:30

9

Math.sin expects a value in radians

System.out.println("Sin 30 = "+ Math.sin(Math.toRadians(30)));

answered Apr 08 '16 at 23:30

Reimeus

score 2 · Accepted Answer · answered Apr 08 '16 at 23:32

2

Before should transform it in Radiant like this:

  double radians = Math.toRadians(30);
  System.out.println("Sin 30 = "+Math.sin(radians));

answered Apr 08 '16 at 23:32

Abdelhak

2 Answers2