Решите cos^2(2x-π/4)=3/4

Question

Решите
cos^2(2x-π/4)=3/4

Answer 1

Cos^2(α) = (1+cos2α)/2
то есть наше выражение приводим к виду:
(1+(cos(4x - π/2)))/2 = 3/4
1+cos(4x - π/2) = 3/2
cos(4x - π/2) = 1/2
4x - π/2 = π/3 (так как cos(π/3) = 1/2)
4x = 5π/6
x = 5π/24