sin²x-sin2x-3cos²x=0

sin^2 x-2sin x cos c - 3 cos^2 x = 0( : cos ^ 2 x) tg ^ 2 x - 2 tg x - 3 = 0tg x = tt^2 - 2t - 3 =0t1 = 3t2 = -11) tg x = 3x = arctg 3  + pi n 2) tg x = -1x =  - pi / 4 + pi n