Question

Решить уравнение: cos(pi/6 - 2x) = -1

Answer 1

$cos(pi/6 - 2x) = -1;$

$arccos(cos(pi/6 - 2x)) = arccos(-1);$

$pi/6 - 2x = pi-arccos(1);$

$pi/6 - 2x = pi+2pi k; kin Z$

$- 2x =frac{5 pi}{6}+2pi k; kin Z$

$x =-frac{5 pi}{12}-pi k; kin Z$