Question

Помогите пожалуйста​

Answer 1

$2x = \frac{\pi}{4} + 2\pi \: n \\ 2x = - \frac{\pi}{4} + 2\pi \: n \\ x = \frac{\pi}{8} + \pi \: n \\ x = - \frac{\pi}{8} + \pi \: n$