A) \[(2n+1)\frac{\pi }{4}\]
B) \[(2n+1)\frac{\pi }{10}\]
C) \[n\pi +\frac{\pi }{2}\]or \[\frac{n\pi }{5}+\frac{\pi }{10}\]
D) None of these
Correct Answer: C
Solution :
\[\sec 4\theta -\sec 2\theta =2\] \[\Rightarrow \] \[\cos 2\theta -\cos 4\theta =2\cos 4\theta \cos 2\theta \] \[\Rightarrow \] \[-\cos 4\theta =\cos 6\theta \] \[\Rightarrow \] \[2\cos 5\theta \cos \theta =0\] \[\Rightarrow \] \[H=\frac{h\cot {{15}^{o}}}{\cot {{15}^{o}}-1}\] or \[\frac{n\pi }{5}+\frac{\pi }{10}\].
You need to login to perform this action.
You will be redirected in
3 sec
