Inverse Trigonometric Functions Question 214

Question: If $ k\le {{\sin }^{-1}}x+{{\cos }^{-1}}x+{{\tan }^{-1}}x\le K, $ then

Options:

A) $ k=0,K=\pi $

B) $ k=0,K=\frac{\pi }{2} $

C) $ k=\frac{\pi }{2},K=\pi $

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

We have $ {{\sin }^{-1}}x+{{\cos }^{-1}}x+{{\tan }^{-1}}x=\frac{\pi }{2}+{{\tan }^{-1}}x $

Since $ \frac{-\pi }{2}\le {{\tan }^{-1}}x\le \frac{\pi }{2}\Rightarrow 0\le \frac{\pi }{2}+{{\tan }^{-1}}x\le \pi $ \ $ K=\pi ,k=0 $ .