whats the for this question

Question

if sin3x=cos6x,then x=_____

Answer 1

Use the identity
cos 2A = 1 - 2sin^2 A
cos 6x = 1 - 2sin^2 (3x)

sin 3x = 1 - 2 sin^2 (3x)
2 sin^2 (3x) + sin 3x - 1 = 0
(sin 3x + 1)(2sin 3x - 1) = 0
sin 3x = -1 or sin 3x = 1/2
3x = 270° or 3x = 30° or 150°
x = 90° or x = 10° or 50°

in radians x = π/18 , 5π/18, π/4