2sin квадрат x+cos4x=0 помогите плиззззз

2 * sin²x + cos 4*x = 1 - cos(2*x) + 2*cos²(2*x) - 1 = 2 * cos²(2*x) - cos (2*x) = 0

cos (2*x) * (2 * cos (2*x) - 1) = 0

1) cos (2*x) = 0                      2)  cos (2*x) = 1/2

  2 * x = π / 2 + π * n                   2*x = ± π / 3 + 2 * π * n

  x = π / 4 + π * n / 2                      x = ± π / 6 + π * n