Question

Чему равен arccos(cos12)?​

Answer 1

$arccos\left ( cos12 \right )=x\\cos12=cosx\Rightarrow x=\pm 12+2\pi k\\D_f=\left [ -1;1 \right ]\Rightarrow x=-12+2\pi+2\pi=-4\left ( 3-\pi \right )$