Mathematics · Functions

JEE Main 2024 — 5 April, Shift 2 — Question 11

Let f, g:R→Rf, \mathrm{~g}: \mathrm{R} \rightarrow \mathrm{R} be defined as : f(x)=∣x−1∣f(\mathrm{x})=|\mathrm{x}-1| and g(x)={ex,x≥0x+1,x≤0\text{g}\left( \text{x} \right)=\left\{ \begin{matrix}{{\text{e}}^{\text{x}}}, & \text{x}\ge 0 \\\text{x}+1, & \text{x}\le 0 \\\end{matrix} \right.. Then the function f( g(x))f(\mathrm{~g}(\mathrm{x})) is

  1. Option A:

    neither one-one nor onto.

    Correct
  2. Option B:

    one-one but not onto.

  3. Option C:

    both one-one and onto

  4. Option D:

    onto but not one-one.

Answer: A

Step-by-step solution

f(g(x))=∣g(x)−1∣f\left( g\left( x \right) \right)=\left| g\left( x \right)-1 \right| fog(x)=[∣ex−1∣x≥0∣x+1−1∣x≤0\text{fog(x)}=\left[ \begin{matrix}\left| {{e}^{x}}-1 \right| & x\ge 0 \\\left| x+1-1 \right| & x\le 0 \\\end{matrix} \right.

fog(x)=[ex−1x≥0−xx≤0\left[ \begin{matrix}{{e}^{x}}-1 & x\ge 0 \\-x & x\le 0 \\\end{matrix} \right.

Solution figure

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Mathematics
Chapter
Functions
Topic
One-One, many-one, onto, into, bijective functions
Let f, g : R rightarrow R be defined as : f( x )= x -1 and g ( x )= \… | JEE Main 2024 PYQ with Solution · DhiX AI