Question

Решите уравнение: Cos2x=0!​

Answer 1

$\displaystyle \cos2x =0$

Т.к. |x| ≤1, то

$\displaystyle 2x = \pm arccos0+2\pi n, n\in \Z$

$\displaystyle 2x =\pm \frac{\pi}{2} +2\pi n, n \in \Z|:2$

$\displaystyle \boldsymbol{ x = \pm \frac{\pi}{4}+\pi n, n \in \Z}$