Question

Помогите пожалуйста cos3x =sin3x

Answer 1

$\cos(3x) = \sin(3x) \\ \sin(3x) = 0 \\ x = \frac{k\pi}{3} \\ \frac{ \cos(3x) }{ \sin(3x) } = 1 \\ \cot(3x) = 1 \\ 3x = arccot(1) \\ 3x = \frac{\pi}{4} \\ 3x = \frac{\pi}{4} + k\pi \\ x = \frac{\pi}{12} + \frac{k\pi}{3}$