10 sin^2x+11 sin2x+6cos2x=-6

10 sin^2x + 11 sin2x + 6cos2x = - 6 10 sin^2x + 22 sinx cosx + 6(cos^2x - sin^2x) = - 6* 1 10 sin^2x + 22 sinx cosx + 12cos^2x =   0  /:cos^2x ≠ 0 10 tg^2x + 22 tgx + 12 = 0 tgx = t 10 t + 22t + 12 =0 D = 484 - 480 = 4 t = ( - 22 + 2)/ 20 = - 20/20 = - 1 t = ( - 22 - 2)/ 20 = - 24/20 = - 6/5 1) tgx = - 1 ==> x = - pi/4 + pik, k ∈Z 2) tgx = - 6/5 ===> x = - arctg(6/5) + pik, k ∈Z ОТВЕТ: x = - pi/4 + pik, k ∈Z x = - arctg(6/5) + pik, k ∈Z