Sin(п/2-2х) + 2сos(п-2х) ≤√3/2

[latex]sin(\frac{\pi}{2}-2x)+2cos(\pi-2x) \leq \frac{\sqrt3}{2}\\cos2x-2cos2x \leq \frac{\sqrt3}{2}\\-cos2x \leq \frac{\sqrt3}{2}\\cos2x \geq -\frac{\sqrt3}{2}\\-\frac{5\pi}{6}+2\pi n \leq 2x \leq \frac{5\pi}{6}+2\pi n\\-\frac{5\pi}{12}+\pi n \leq x \leq \frac{5\pi}{12}+\pi n, \; n\in Z[/latex]