Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Inverse Trigonometric Functions

Question:

The set of value sof x satisfying $|sin^{-1}x|<|cos^{-1}x|$, is

Options:

$[-1, 1/\sqrt{2}]$

$[-1, 1/\sqrt{2}] ∪ [1/\sqrt{2},1]$

$(-1, 1/\sqrt{2})$

none of these

Correct Answer:

$[-1, 1/\sqrt{2}]$

Explanation:

We know that $0 ≤ cos^{-1} x ≤ \pi $.

$ ∴ |cos^{-1}x|= cos^{-1} x$

It is evident from the graphs of $y = |sin^{-1}x|$ and $y = |cos^{-1}x|$ that

$|sin^{-1}x| < |cos^{-1}x|$ for all x ∈$ [-1, 1/\sqrt{2}]$