Inverse Trigonometric Functions Question 158

Question: $ {{\tan }^{-1}}\frac{1}{\sqrt{x^{2}-1}}= $

Options:

A) $ \frac{\pi }{2}+cose{c^{-1}}x $

B) $ \frac{\pi }{2}+{{\sec }^{-1}}x $

C) $ cose{c^{-1}}x $

D) $ {{\sec }^{-1}}x $

Show Answer

Answer:

Correct Answer: C

Solution:

$ {{\tan }^{-1}}\frac{1}{\sqrt{x^{2}-1}}={{\tan }^{-1}}\frac{1}{\sqrt{cose{c^{2}}\theta -1}} $ (Putting $ x=cosec\theta ) $

$ ={{\tan }^{-1}}\frac{1}{\cot \theta }=\theta =cose{c^{-1}}x $ .