Question

помогите ..................

Answer 1

$2sinx+ \sqrt 2 =0$
$2sinx= - \sqrt 2$
$\displaystyle sinx= -\frac{ \sqrt 2}{2}$
$\displaystyle \boxed{x= (-1)^{n+1} \frac{ \pi}{4}+ \pi n, n \in Z}$