Как решить такое уравнение? 2*cos^2(x/6)+cos(pi/4)= 1-2*sin^2(pi/8)

2Cos²(x/6)+√2/2 = Cosπ/4
2Cos²(x/6) = 0
Cos(x/6) = 0
x/6 = π/2 + πk, k∈z
x = 3π + 6πk, k∈Z

2*cos^2(x/6) + √2/2=1-2*(1-cos(pi/4))/2
2*cos^2(x/6) +√2/2 = √2/2
cos(x/6)=0
x/6=Pi/2 + Pi*n; n∈z
x=Pi*3+6*Pi*n; n∈z