F`(x)=cosx+sinx
ВСЁ!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Cos^2x-sin^2x=3+7cosx
cos^2x-1+cos^2x=3+7cosx
2cos^2x-7cosx-4=0
cosx=y,-1<=y<=1
2y^2-7y-4=0
D=49+32=81
y1=(7+9)/4=4
y2=(7-9)/4=-1/2
cosx=-1/2
x=+-2π/3+2πn
(х^2 - x) - (y^2 + y) = x(x-1) - y(y+1)