MCQ
${\cos ^{ - 1}}\left( {\frac{{3 + 5\cos x}}{{5 + 3\cos x}}} \right)$ is equal to
- A${\tan ^{ - 1}}\left( {\frac{1}{2}\tan \frac{x}{2}} \right)$
- B$2{\tan ^{ - 1}}\left( {2\tan \frac{x}{2}} \right)$
- C$\frac{1}{2}{\tan ^{ - 1}}\left( {2\tan \frac{x}{2}} \right)$
- ✓$2{\tan ^{ - 1}}\left( {\frac{1}{2}\tan \frac{x}{2}} \right)$