Question

20БАЛЛОВ Решите неравенства:

1. Cosx<1/2

2.tgx> - корень из 3/3

Answer 1

$1)\; \; cosx\ \textless \ \frac{1}{2}\\\\\frac{\pi }{3}+2\pi n\ \textless \ x\ \textless \ \frac{5\pi }{3}+2\pi n\; ,\; n\in Z\\\\2)\; \; tgx\ \textgreater \ -\frac{\sqrt3}{3}\\\\-\frac{\pi}{6}+\pi k\ \textless \ x\ \textless \ \frac{\pi}{2}+\pi k\; ,\; k\in Z$