50 ! решить уравнение 1)sin2x-sin3x+sin8x-sin7x=0 2)3sin2x+cos2x=2

2)3sin2x + cos2x = 2
6sinxcosx + cos²x-sin²x = 2sin²x+2cos²x
6sinxcosx - cos²x - 3sin²x = 0

-  -  = 0

3tg²x - 6tgx +1 = 0
Замена
tgx = a
3a² - 6a +1 = 0
D = 36 - 4*3 = 24
a₁ = 
a₂ = 
tgx =
x = arctg()+πk, k∈z
tgx =
x = arctg()+πK, k∈z