Тригонометрия 3sin^2 x x-8 sinx cosx +7 cos^2 x =1 решите )

3sin²x-8sinx*cosx+7cos²x=1
3sin²x-8sinx*cosx+7cos²x-sin²x-cos²x=0
2sin²x-8sinx*cosx+6cos²x=0 | :cos²x≠0
2tg²x-8tgx+6=0
tgx=t
2t²-8t+6=0
t²-4t+3=0
t₁=3, t₂=1
1. tgx=3, x₁=arctg3+πn, n∈Z

2. tgx=1, x₂=π/4+πn,n∈Z