2Sin²3x + Cos²3x + Sin3x = 1
2Sin²3x + 1 - Sin²3x + Sin3x = 1
Sin²3x + Sin3x = 0
Sin3x(Sin3x + 1) = 0
2Sin²3x + Cos²3x + Sin3x = 1
2Sin²3x + 1 - Sin²3x + Sin3x = 1
Sin²3x + Sin3x = 0
Sin3x(Sin3x + 1) = 0