Решебник по алгебре и начала математического анализа 11 класс Колягин Задание 39

\[- \frac{\pi}{2} \leq x \leq \frac{3\pi}{2}.\]

\[1)\cos{2x} = \frac{1}{2}\]

\[2x = \pm \frac{\pi}{3} + 2\pi n\]

\[x = \pm \frac{\pi}{6} + \pi\text{n.}\]

\[Ответ:\ \]

\[- \frac{\pi}{6};\ \frac{\pi}{6};\ \frac{5\pi}{6};\ \frac{7\pi}{6}.\]

\[2)\cos{3x} = \frac{\sqrt{3}}{2}\]

\[3x = \pm \frac{\pi}{6} + 2\pi n\]

\[x = \pm \frac{\pi}{18} + \frac{2\pi n}{3}.\]

\[Ответ:\ \]

\[- \frac{\pi}{18};\ \frac{\pi}{18};\ \frac{11\pi}{18};\ \frac{13\pi}{18};\ \frac{23\pi}{18};\ \frac{25\pi}{18}.\]