Mathematics · Definite Integration

JEE Main 2025 — 4 April, Morning Shift — Question 32

The value of ∫−11(1+∣x∣−x)ex+(∣x∣−x)e−xex+e−xdx\int_{-1}^{1} \frac{(1+\sqrt{|x|-x}) e^{x}+(\sqrt{|x|-x}) e^{-x}}{e^{x}+e^{-x}} d x is equal to

  1. Option A:

    2+2232+\frac{2 \sqrt{2}}{3}

  2. Option B:

    1+2231+\frac{2 \sqrt{2}}{3}

    Correct
  3. Option C:

    1−2231-\frac{2 \sqrt{2}}{3}

  4. Option D:

    3−2233-\frac{2 \sqrt{2}}{3}

Answer: B

Step-by-step solution

I=∫−11(1+∣x∣−x)ex+(∣x∣−x)e−xex+e−xdxI=\int_{-1}^{1} \frac{(1+\sqrt{|x|-x}) e^{x}+(\sqrt{|x|-x}) e^{-x}}{e^{x}+e^{-x}} d x

=∫01((1+∣x∣−x)ex+(∣x∣−x)e−xex+e−x+((1+∣x∣+x)e−x+(∣x∣+x)e−xe−x+ex)dx\begin{aligned} & =\int_{0}^{1}\left(\frac{(1+\sqrt{|x|-x}) e^{x}+(\sqrt{|x|-x}) e^{-x}}{e^{x}+e^{-x}}\right. \\& \quad+\left(\frac{(1+\sqrt{|x|+x}) e^{-x}+(\sqrt{|x|+x}) e^{-x}}{e^{-x}+e^{x}}\right) d x \end{aligned} =∫01(1+∣x∣−x+∣x∣+x)(ex+e−x)ex+e−xdx=\int_{0}^{1} \frac{(1+\sqrt{|x|-x}+\sqrt{|x|+x})\left(e^{x}+e^{-x}\right)}{e^{x}+e^{-x}} d x =∫01(1+∣x∣−x+∣x∣+x)dx=\int_{0}^{1}(1+\sqrt{|x|-x}+\sqrt{|x|+x}) d x

=∫01(1+2x)dx=x∣01+2x3232∣01=\int_{0}^{1}(1+\sqrt{2 x}) d x=\left.x\right|_{0} ^{1}+\left.\frac{\sqrt{2} x^{\frac{3}{2}}}{\frac{3}{2}}\right|_{0} ^{1}

=1+223=1+\frac{2 \sqrt{2}}{3}

Answer key and solution verified before publishing.

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Exam
JEE Main 2025
Subject
Mathematics
Chapter
Definite Integration
Topic
Evaluation of Definite Integrals