Тригонометрическое неравенство (желательно по графику)

Решите задачу:

$cos(1,5x+\frac{\pi}{6})\ \textgreater \ \frac{\sqrt3}{2}\\\\-\frac{\pi}{6}+2\pi n\ \textless \ 1,5x+\frac{\pi}{6}\ \textless \ \frac{\pi}{6}+2\pi n\; ,\; n\in Z\\\\-\frac{\pi}{3}+2\pi n\ \textless \ 1,5x\ \textless \ 2\pi n\; ,\; n\in Z\\\\-\frac{2\pi}{9}+\frac{4\pi n}{3}\ \textless \ x\ \textless \ \frac{4\pi n}{3}\; ,\; n\in Z$