Question

решите уравнение, срочно

$8 sin{}^{2} x + cos(x) + 1 = 0$

Answer 1

$8sin^2x+cosx+1=0\ 8-8cos^2x+cosx+1=0\-8cos^2x+cosx+9=0\D=1+288=17^2\cosx_{1,2}= frac{-1б17}{-16} = |{ {{-1} atop { frac{18}{16} }} right. \cosx=-1\x= pi +2 pi n,NprinZ$, 
Ответ: $x= pi +2 pi n$, N∈Z