6sin^2x+sinxcosx-cos^2x-2sin^2x-2cos^2x=0 4sin^2x+sinxcosx-3cos^2x=0 :cos^2x 4tg^2x+tgx-3=0 tgx=-1 tgx=3/4 x=arctg3/4+Пk x=-П/4+Пk