Find the general solution for each of the following equations: cos 4 x = cos 2 x

Question

Philoid · Accepted Answer

Given cos 4 x = cos 2 x

⇒ cos 4x – cos 2x = 0

⇒

⇒ sin 3x sin x = 0

⇒ sin 3x = 0 or sin x = 0

∴

⇒