2cos (в квадрате) 2x-1=sin4x

Question

2cos (в квадрате) 2x-1=sin4x

Answer 1

2 cos^2 (2x) - 1 = sin4x
cos4x - sin4x = 0   /: (-1)
sin4x - cos4x = 0  /:cos4x≠0
tg4x - 1 = 0
tg4x = 1
4x  = pi/4 + pik
x = pi/16 + pik/4 , k ∈Z