Quantitative Aptitude Ques 885

Question: The value of $ \frac{\tan 27{}^\circ +\cot 63{}^\circ }{\tan 27{}^\circ (\sin 25{}^\circ +\cos 65{}^\circ )} $ is

Options:

A) $ cosec25{}^\circ $

B) $ 2\tan 27{}^\circ $

C) $ \sin 25{}^\circ $

D) $ \tan 65{}^\circ $

Show Answer

Answer:

Correct Answer: A

Solution:

  • Given, $ \frac{\tan 27{}^\circ +\cot 63{}^\circ }{\tan 27{}^\circ (\sin 25{}^\circ +\cos 65{}^\circ )} $ $ =\frac{\tan 27{}^\circ +\cot (90{}^\circ -27{}^\circ )}{\tan 27{}^\circ [\sin 25{}^\circ +\cos (90{}^\circ -25{}^\circ )]} $ $ [\because \cot (90{}^\circ -\theta )=tan\theta andcos(90{}^\circ -\theta )=\sin \theta ] $ $ =\frac{\tan 27{}^\circ +\tan 27{}^\circ }{\tan 27{}^\circ (\sin 25{}^\circ +\sin 25{}^\circ )} $ $ =\frac{2\tan 27{}^\circ }{\tan 27{}^\circ (2\sin 25{}^\circ )}=cosec25{}^\circ $