Mathematics · Differential Equations

JEE Main 2024 — 4 April, Shift 1 — Question 4

If the solution y=y(x)y=y(x) of the differential equation (x4+2x3+3x2+2x+2)dy−(2x2+2x+3)dx=0\left(x^{4}+2 x^{3}+3 x^{2}+2 x+2\right) d y-\left(2 x^{2}+2 x+3\right) d x=0 satisfies y(−1)=−π4y(-1)=-\frac{\pi}{4}, then y(0)y(0) is equal to :

  1. Option A:

    −π12-\frac{\pi}{12}

  2. Option B:

    00

  3. Option C:

    π4\frac{\pi}{4}

    Correct
  4. Option D:

    π2\frac{\pi}{2}

Answer: C

Step-by-step solution

∫dy=∫(2x2+2x+3)x4+2x3+3x2+2x+2dx\int d y=\int \frac{\left(2 x^{2}+2 x+3\right)}{x^{4}+2 x^{3}+3 x^{2}+2 x+2} d x

y=∫(2x2+2x+3)(x2+1)(x2+2x+2)dxy=\int \frac{\left(2 x^{2}+2 x+3\right)}{\left(x^{2}+1\right)\left(x^{2}+2 x+2\right)} d x

y=∫dxx2+2x+2+∫dxx2+1y=\int \frac{d x}{x^{2}+2 x+2}+\int \frac{d x}{x^{2}+1}

y=tan⁡−1(x+1)+tan⁡−1x+Cy=\tan ^{-1}(x+1)+\tan ^{-1} x+C

y(−1)=−π4y(-1)=\frac{-\pi}{4}

−π4=0−π4+C⇒C=0\frac{-\pi}{4}=0-\frac{\pi}{4}+\mathrm{C} \Rightarrow \mathrm{C}=0

⇒y=tan⁡−1(x+1)+tan⁡−1x\Rightarrow \mathrm{y}=\tan ^{-1}(\mathrm{x}+1)+\tan ^{-1} \mathrm{x}

y(0)=tan⁡−11=π4y(0)=\tan ^{-1} 1=\frac{\pi}{4}

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Mathematics
Chapter
Differential Equations
Topic
Methods of solving a First Order,First Degree Differential
If the solution y=y(x) of the differential equation (x 4 +2 x 3 +3 x… | JEE Main 2024 PYQ with Solution · DhiX AI