Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Relations and Functions

Question:

Let \(f:\mathbb{R}\rightarrow\mathbb{R}\) defined by \(f(x)=5x+4\) then \(f^{-1}(x)\) is

Options:

\(\frac{x-4}{5}\)

\(\frac{x+4}{5}\)

\(\frac{x-4}{4}\)

f is non invertible

Correct Answer:

\(\frac{x-4}{5}\)

Explanation:

\(f(x)=5x+4\)

so $y=5x+4⇒y-4=5x$

$⇒x=\frac{y-4}{5}$

$f^{-1}(x)=\frac{x-4}{5}$