1-2sinxcosx-sin^2x=0

cos^2x+sin^2x-2sinxcos-sin^2x=0cos^2x-2sinxcosx=0cosx(cosx-2sinx)=0cosx=0  x=п/2+пn cos-2sinx=0 : cosx1-2tgx=0-2tgx=-1tgx=1/2x=arctg1/2+пn