ОГРОМНАЯ ПРОСЬБА arccos(cos 10)

Решите задачу:

$arccos(cos \alpha )= \alpha \; ,\; \; esli\; \; \; \underline {\underline {0 \leq \alpha \leq \pi }}\\\\10\; radian\approx 573^\circ =3\cdot 180^\circ +33^\circ \in 3\; chetverti\\\\3\pi \ \textless \ 10\, \; \ \textless \ 4\pi \\\\3\pi -4\pi \ \textless \ 10-4\pi \ \textless \ 4\pi -4\pi \\\\-\pi \ \textless \ 10-4\pi \ \textless \ 0\\\\0\ \textless \ 4\pi -10\ \textless \ \pi \; \; \Rightarrow \; \; arccos(cos10)=arccos(4\pi -10)=4\pi -10$