2 cos ( x/3-pi/4 ) =1

Решение
2 cos ( x/3-pi/4 ) =1
cos (x/3 - π/4) = 1/2
x/3 - π/4 = (+ -)arccos(1/2) + 2πk, k∈Z
x/3 - π/4 = (+ -)(π/3) + 2πk, k∈Z
x/3 = (+ -)(π/3) + π/4 + 2πk, k∈Z
x = (+ -)(π) + 3π/4 + 2πk, k∈Z