Решите уравнение \(\cos x = -1\) .

• \(x = \pi + 2\pi k, k \in Z\)
• \(x = \frac{\pi}{2} + \pi k, k \in Z\)
• \(x = \frac{\pi}{2} + 2\pi k, k \in Z\)
• \(x = 2\pi k, k \in Z\)