Решебник по геометрии 9 класс Мерзляк Задание 9

\[1)\sin{150{^\circ}} = \sin(90{^\circ} + 60{^\circ}) =\]

\[= \cos{60{^\circ}} = \frac{1}{2};\]

\[2)\cos{150{^\circ}} = \cos(90{^\circ} + 60{^\circ}) =\]

\[= - \sin{60{^\circ}} = - \frac{\sqrt{3}}{2};\]

\[3)\ tg\ 150{^\circ} = \frac{\sin{150{^\circ}}}{\cos{150{^\circ}}} =\]

\[= \frac{1}{2}\ :\left( - \frac{\sqrt{3}}{2} \right) = - \frac{1}{\sqrt{3}};\]

\[4)\ ctg\ 150{^\circ} = \frac{1}{tg\ 150{^\circ}} = - \sqrt{3}.\]