Решить уравнение (sin^2)8x=2(sin^2)4x

(sin^2)(8x) = 2(sin^2)(4x)
2*[sin(4x)]*[cos(4x)] - 2*sin(4x) = 0
[sin(4x)]*[cos(4x) - 1] = 0
1)  sin4x = 0 
4x = πn, n∈Z
x1 = (πn)/4, n∈Z
2)  cos4x = 1
4x = 2πk, k∈Z
x2 = (πk)/2, k∈Z