Mathematics · Differential Equations

JEE Main 2026 — 5 April, Morning Shift — Question 48

Let y=y(x)\mathrm{y}=\mathrm{y}(\mathrm{x}) be the solution of the differential equation xsin⁡(yx)dy=(ysin⁡(yx)−x)dx,y(1)=π2x \sin \left(\frac{y}{x}\right) d y=\left(y \sin \left(\frac{y}{x}\right)-x\right) d x, y(1)=\frac{\pi}{2} and let α=cos⁡(y(e12)e12)\alpha=\cos \left(\frac{\mathrm{y}\left(\mathrm{e}^{12}\right)}{\mathrm{e}^{12}}\right). Then the number of integral value of pp, for which the equation x2+y2−2px+2py+α+2=0x^{2}+y^{2}-2 p x+2 p y+\alpha+2=0 represents a circle of radius r≤6r \leq 6, is ____\_\_\_\_

Answer: 11

Numerical answer — enter this value.

Step-by-step solution

sin⁡yxdydx=yxsin⁡yx−1\sin \frac{\mathrm{y}}{\mathrm{x}} \frac{\mathrm{dy}}{\mathrm{dx}}=\frac{\mathrm{y}}{\mathrm{x}} \sin \frac{\mathrm{y}}{\mathrm{x}}-1 put y=tx⇒dydx=t+xdtdxy=t x \Rightarrow \frac{d y}{d x}=t+x \frac{d t}{d x} sin⁡t(t+xdtdx)=tsin⁡t−1\sin t\left(t+x \frac{d t}{d x}\right)=t \sin t-1 xsin⁡tdtdx+1=0\mathrm{x} \sin \mathrm{t} \frac{\mathrm{dt}}{\mathrm{dx}}+1=0 sin⁡tdt+dxx=0\sin t d t+\frac{d x}{x}=0 ⇒−\Rightarrow- cost +ℓnx=C+\ell \mathrm{nx}=\mathrm{C} ⇒−cos⁡(yx)+ℓnx=C\Rightarrow-\cos \left(\frac{\mathrm{y}}{\mathrm{x}}\right)+\ell \mathrm{nx}=\mathrm{C} y(1)=π2⇒C=0\mathrm{y}(1)=\frac{\pi}{2} \Rightarrow \mathrm{C}=0 ⇒cos⁡(yx)=ln⁡x\Rightarrow \cos \left(\frac{\mathrm{y}}{\mathrm{x}}\right)=\ln \mathrm{x} cosec⁡(y(e12)e12)=12⇒α=12\operatorname{cosec}\left(\frac{\mathrm{y}\left(\mathrm{e}^{12}\right)}{\mathrm{e}^{12}}\right)=12 \Rightarrow \alpha=12 x2+y2−2px+2py+14=0x^{2}+y^{2}-2 p x+2 p y+14=0 r=p2+p2−14\mathrm{r}=\sqrt{\mathrm{p}^{2}+\mathrm{p}^{2}-14} ⇒r≤6⇒r2≤36\Rightarrow \mathrm{r} \leq 6 \Rightarrow \mathrm{r}^{2} \leq 36 2p2−14≤362 \mathrm{p}^{2}-14 \leq 36 p2≤25\mathrm{p}^{2} \leq 25 p∈[−5,5]\mathrm{p} \in[-5,5] number of integral value of p=11p=11

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Subject
Mathematics
Chapter
Differential Equations
Topic
Methods of solving a First Order,First Degree Differential
Let y = y ( x ) be the solution of the differential equation x sin… | JEE Main 2026 PYQ with Solution · DhiX AI