sin²x+sin²2x=sin²3x
sin²x + sin²2x - sin²3x = 0
(Sin²x - Sin²3x) + Sin²2x = 0
(Sinx - Sin3x) (Sinx + Sin3x) + Sin²2x = 0
2Sin(-x)Cos2x *2Sin2xCosx +Sin²2x = 0
-2*2SinxCos2xSin2xCosx + Sin²2x = 0
-Sin2xSin4x +Sin²2x = 0
Sin2x( -Sin4x +Sin2x) = 0
Sin2x = 0 или -Sin4x +Sin2x = 0
2x = nπ, n∈Z 2Sin(-x)Cos3x = 0
x = nπ/2, n ∈Z Sinx = 0 Cos3x = 0
x = πk , k∈Z 3x = π/2 + πm, m ∈Z
x = π/6 + πm/3 , m ∈Z