(x^2+рi^2/4+pix-pi^2/4)(cosx-sinx)=0 cosx>=sinx
x^2+pix=0
x=0 x=pi x=П/4+Пk
x=0 x=П/4+Пk
cosx<sinx
x^2+pi^2/2+pix=0
2x^2+2pix+pi^2=0
x=pi+-sqrt(pi^2-2pi^2)/2
D<0
(x^2+рi^2/4+pix-pi^2/4)(cosx-sinx)=0 cosx>=sinx
x^2+pix=0
x=0 x=pi x=П/4+Пk
x=0 x=П/4+Пk
cosx<sinx
x^2+pi^2/2+pix=0
2x^2+2pix+pi^2=0
x=pi+-sqrt(pi^2-2pi^2)/2
D<0