Question

Range of $f(x)={\sin }^{-1}x+{\tan }^{-1}x+{\sec }^{-1}x$ is

• A. $\left(\frac{\pi }{4},\frac{3\pi }{4}\right)$
• B. $\left[\frac{\pi }{4},\frac{3\pi }{4}\right]$
• C. $\left\{\frac{\pi }{4},\frac{3\pi }{4}\right\}$
• D. None of these

Answer 1

Answer: (D)

Correct answer is (d) None of these