4-8sin^2x+4sinx-1=0
8sin^2x-4sinx-3=0
sinx=(2+-sqrt(4+24))/8
sinx=(1+sqrt(7))/4
sinx=(1-sqrt(7))/4
x=arcsin((1+-sqrt(7))/4)+2Пk
4cos^2x+4sinx=1
4*(1-sin^2x)+4sinx=1
4-4sin^2x+4sinx=1
4sin^2x-4sinx-3=0
sinx=t, |t| <=1
=>
4t^2-4t-3=0
t_1=12/8 > 1 - посторонний
t_2=-1/2
=>
sinx=-1/2
=>
x=-pi/6+2*pi*n, n in Z
x=-5*pi/6+2*pi*n, n in Z
