Решите уравнение \(cos^2\frac{x}{2} = sin^2\frac{x}{2}\)

• \(\frac{\pi}{2} + \pi n, n \in Z\)
• \(\frac{\pi}{4} + \pi n, n \in Z\)
• \(\frac{\pi}{2} + 2\pi n, n \in Z\)