Решите уравнение cos^2 x + 1 = sin^2 x

cos^2 x + 1 = sin^2 x
cos^2 x + cos^2 x + sin^2 x = sin^2 x
cos^2 x + cos^2 x = 0
2cos^2 x = 0
cos^2 x  = 0
cos(x)=0
x = π n - π/2, n ∈ Z