Question

Решите неравенство:
cosx < 1/2

Answer 1

cosx < $\frac{1}{2}$
arccos($\frac{1}{2}$) + 2πn < x < 2π - arccos($\frac{1}{2}$) + 2πn
$\frac{\pi}{3}$ + 2πn < x < 2π - $\frac{\pi}{3}$ + 2πn
$\frac{\pi}{3}$ + 2πn < x < $\frac{5\pi}{3}$ + 2πn
[!] n ∈ Z