Find the principal values of the following:
1. \(sin^{-1}({-\frac{1}{2}})\)
2. \(cos^{-1}({\frac{\sqrt{3}}{2}})\)
5. \(cos^{-1}({-\frac{1}{2}})\)
7. \(sec^{-1}({\frac{2}{\sqrt 3}})\)
9. \(cos^{-1}({-\frac{1}{\sqrt 2}})\)
Find the values of the following:
11. \(tan^{-1}(1)\)+\(cos^{-1}({-\frac{1}{\sqrt 2}})\)+\(sin^{-1}({-\frac{1}{\sqrt 2}})\).
12. \(cos^{-1}({\frac{1}{\sqrt 2}})\)+2\(sin^{-1}({\frac{1}{\sqrt 2}})\).
(B) \(-\frac{\pi}{2}\le y \le -\frac{\pi}{2}\)
(D) \(-\frac{\pi}{2} < y < -\frac{\pi}{2}\)