Ques. 1JEE Main 2025, 22 January (Morning Shift)
Let x=x(y) be the solution of the differential equation y2 dx+ (x- 1y )dy=0. If x(1)=1, then x ( 12 ) is :
- 32+e
- 12+e
- 3+e
- 3-e
Answer
(4) 3-e
Solution
With y as the independent variable the equation is linear: dxdy+ xy2= 1y3, I.F. =e-1/y.
x e-1/y= e-1/yy3dy; put t= 1y: =- te-tdt=(t+1)e-t+C
x= 1y+1+Ce1/y; x(1)=1 C=- 1e
x ( 12 )=2+1- 1e e2=3-e
Answer: (4)