How do I solve 4 sin x + 9 cos x = 0 for 0 < x < 360 ?

1 Answer

Refer to explanation

Explanation:

We have that
4 sinx + 9 cosx = 0=> 4 sinx = −9 cosx => sinx/cosx = −9/4 => tanx = −9/4

x = tan^(-1)(−9/4) + pi*k, for all integers k

For 0° < x < 360°
x = tan^(-1)(−9/4) + 180 ≈ 113.96°
x = tan^(-1)(−9/4) + 360 ≈ 293.96°