Value of cosinus 90 degree

Question

Using java.lang.Math functions. Could someone exaplain why the value of cos(90) = 6.1 ?

    for (int i = 0; i < 91; i++) {
        System.out.println(i  + " = " + cos(toRadians(i)));
    }

Output is:

0 = 1.0
1 = 0.9998476951563913
2 = 0.9993908270190958
...
89 = 0.0174524064372836
90 = 6.123233995736766E-17

You answer is here : https://stackoverflow.com/a/5263743/3780625 — Maxouille, Mar 08 '19 at 14:27
It's **not** 6.1, but 0.000000000000000061. Notice the `E-17` after the number. — JimmyB, Mar 08 '19 at 14:28

score 5 · Accepted Answer · edited Mar 08 '19 at 14:30

5

Please note the exponential notation. The output

90 = 6.123233995736766E-17

does not indicate a value of 6.1, but a value of 6.1*10^{-17}.

Which is close to zero (0). It is not absolute zero because of precision issues with floating points.

edited Mar 08 '19 at 14:30

Zabuzard

answered Mar 08 '19 at 14:28

Codor

1 Answers1