3cos²x-2*5sin2x-2sin²x=0

3cos^2(x) - 5sin^2(x) - sin2x = 0 3cos^2(x) - 5sin^2(x) -2sinxcosx = 0  5tg^2(x) + 2tgx - 3 = 0 D = 64 1) tgx = -1 x = - П/4 + Пn 2) tgx = 0,6 x = arctg0,6 + Пn