Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Relations and Functions

Question:

If a function $f: R_{+} → [-5, \infty)$ given by $f(x)=9 x^2+6 x-5$ is one-one and onto, then $f^{-1}(y)$ is _______.

Options:

$\frac{\sqrt{y+1}+6}{3}$

$\frac{\sqrt{y+5}+1}{3}$

$\frac{\sqrt{(y+6)}+1}{3}$

$\frac{\sqrt{(y+6)}-1}{3}$

Correct Answer:

$\frac{\sqrt{(y+6)}-1}{3}$

Explanation:

The correct answer is Option (4) - $\frac{\sqrt{(y+6)}-1}{3}$