Sin2x - 22Cos^2x+10*1 =0
Sin2x - 22Cos²x + 10*(Sin²x + Cos²x) = 0
2SinxCosx -22Cos²x + 10Sin²x +10Cos²x = 0
2SinxCosx -12Cos²x + 10Sin²x = 0
SinxCosx - 6Cos²x +5Sin²x = 0 | : Cos²x
tgx -6 +5tg²x = 0
tgx = t
5t² +t - 6 = 0
D = b² -4ac = 121
t₁ = 1 t₂= -1,2
tgx = 1 tgx = -1,2
x = π/4 + πk , k∈Z x = arctg(-1,2) + πn , n ∈Z