sin^2x-5 cosx=sinx*cosx-5sinx sin^2x - 5cosx - sinxcosx + 5sinx = 0 sin^2x + 5sinx - 5cosx - sinxcosx = 0 sinx(sinx + 5) - cosx(5 + sinx) = 0 (sinx - cosx)(sinx + 5) = 0 sinx - cosx = 0 | : cosx tgx - 1 = 0 tgx = 1 x = arctg1 + pin x = pi/4 + pin, n = Z sinx + 5 = 0 sinx = -5 x = (-1)^n * -arcsin5 + pin, n=Z