Mathematics · Differential Equations

JEE Main 2025 — 7 April, Morning Shift — Question 26

Let y=y(x)y=y(x) be the solution curve of the differential equation x(x2+ex)dy+(ex(x−2)y−x3)dx=0x\left(x^{2}+e^{x}\right) d y+\left(e^{x}(x-2) y-x^{3}\right) d x=0, x>0x>0, passing through the point (1,0)(1,0). Then y(2)y(2) is equal to

  1. Option A:

    22+e2\frac{2}{2+e^{2}}

  2. Option B:

    44−e2\frac{4}{4-e^{2}}

  3. Option C:

    22−e2\frac{2}{2-e^{2}}

  4. Option D:

    44+e2\frac{4}{4+e^{2}}

    Correct

Answer: D

Step-by-step solution

x(x2+ex)dy+(ex(x−2)y−x3)dx=0x\left(x^{2}+e^{x}\right) d y+\left(e^{x}(x-2) y-x^{3}\right) d x=0

dydx+ex(x−2)x(x2+ex)y=x3x(x2+ex) I.F. =e∫ex(x−2)x(x2+ex)dx=e∫exx+2xex+x2dx−∫2xdx=eln⁡e2+x2∣−2ln⁡x=ex+x2x2∴y(e2+x2x2)=∫dx+c⇒y(ex+x2x2)=x+c\begin{aligned} & \frac{d y}{d x}+\frac{e^{x}(x-2)}{x\left(x^{2}+e^{x}\right)} y=\frac{x^{3}}{x\left(x^{2}+e^{x}\right)} \\& \text { I.F. }=e^{\int \frac{e^{x}(x-2)}{x\left(x^{2}+e^{x}\right)} d x} \\& =e^{\int \frac{e^{x} x+2 x}{e^{x}+x^{2}} d x-\int \frac{2}{x} d x} \\& =e^{\ln e^{2}+x^{2} \mid-2 \ln x} \\& =\frac{e^{x}+x^{2}}{x^{2}} \\& \therefore \quad y\left(\frac{e^{2}+x^{2}}{x^{2}}\right)=\int d x+c \\& \Rightarrow \quad y\left(\frac{e^{x}+x^{2}}{x^{2}}\right)=x+c \end{aligned}

Also, y(1)=0y(1)=0

⇒c=−1\Rightarrow c=-1

∴y(e2+x2x2)=x−1\therefore \quad y\left(\frac{e^{2}+x^{2}}{x^{2}}\right)=x-1

Hence, y(2)=4e2+4y(2)=\frac{4}{e^{2}+4}

Answer key and solution verified before publishing.

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Exam
JEE Main 2025
Subject
Mathematics
Chapter
Differential Equations
Topic
Miscellaneous problems
Let y=y(x) be the solution curve of the differential equation x (x 2… | JEE Main 2025 PYQ with Solution · DhiX AI