Question

Решить неравенство
3)cosx $\leq$ - $\frac{1}{2}$

Answer 1

$cosx \leq -\frac{1}{2}\\\\ \frac{2\pi}{3}+2\pi n\leq x \leq \frac{4\pi}{3}+2\pi n\; ,\; n\in Z$