Question: For any real value of $ \theta , $ $ \sqrt{\frac{\sec \theta -1}{\sec \theta +1}} $ is equal to
Options:
A) $ \cot \theta -cosec\theta $
B) $ \sec \theta -\tan \theta $
C) $ cosec\theta -\cot \theta $
D) $ \tan \theta -\sec \theta $
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Answer:
Correct Answer: C
Solution:
- $ \sqrt{\frac{\sec \theta -1}{\sec \theta +1}}=\sqrt{\frac{(\sec \theta -1)(sec\theta -1)}{(\sec \theta +1)(\sec \theta -1)}} $
$ =\sqrt{\frac{{{(\sec \theta -1)}^{2}}}{{{\sec }^{2}}\theta -1}}=\sqrt{\frac{{{(\sec \theta -1)}^{2}}}{{{\tan }^{2}}\theta }} $
$ =\frac{\sec \theta -1}{\tan \theta }=cosec\theta -\cot \theta $