Inverse Trigonometric Functions Question 183

Question: $ {{\sin }^{-1}}x+{{\sin }^{-1}}\frac{1}{x}+{{\cos }^{-1}}x+{{\cos }^{-1}}\frac{1}{x}= $

Options:

A) $ \pi $

B) $ \frac{\pi }{2} $

C) $ \frac{3\pi }{2} $

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

$ {{\sin }^{-1}}x+{{\sin }^{-1}}\frac{1}{x}+{{\cos }^{-1}}x+{{\cos }^{-1}}\frac{1}{x} $ = $ {{{\sin }^{-1}}(x)+{{\cos }^{-1}}(x)}+{ {{\sin }^{-1}}( \frac{1}{x} )+{{\cos }^{-1}}( \frac{1}{x} ) } $

$ =\frac{\pi }{2}+\frac{\pi }{2}=\pi $ .