Решите уравнение: cosx^2-sinx^2=-1/2

Сos x² - Cos(π/2 - x²) = -1/2-2Sinπ/4·Sin(-π/4 + x²) = -1/2-2·1/√2Sin(x² - π/4) = -1/2Sin(x² - π/4) = √2/4х² - π/4 = (-1)^n arcSin(√2/4) + nπ, n∈Zx² = (-1)^n arcSin(√2/4) + nπ + π/4 , n∈Zx = +-√((-1)^n arcSin(√2/4) + nπ + π/4), n∈2k, k ∈Z