Вычислить \(arccos(-\frac{1}{2})-arcsin(-\frac{\sqrt 2}{2})\)

• \(\frac{11\pi}{12}\)
• \(\frac{7\pi}{4}\)
• \(\frac{\pi}{12}\)
• \(\frac{5\pi}{6}\)
• \(\frac{9\pi}{7}\)