1-2sinxcosx-sin^2x=0
Cos^2x+sin^2x-2sinxcos-sin^2x=0 cos^2x-2sinxcosx=0 cosx(cosx-2sinx)=0 cosx=0 x=п/2+пn cos-2sinx=0 : cosx 1-2tgx=0 -2tgx=-1 tgx=1/2 x=arctg1/2+пn