Question

Cos2x>=-корень3/2
Прошу помощи.

Answer 1

$cos2x \geq -\frac{\sqrt3}2\\\\2x\in[-\frac{5\pi}6+2\pi n;\frac{5\pi}6+2\pi n],n\in Z\\x\in[-\frac{5\pi}{12}+\pi n;\frac{5\pi}{12}+\pi n],n\in Z$