Let y   =   y ( x ) be the solution of the differential equation x 3   d y   +   (…

Let y = y(x) be the solution of the differential equation x3 dy + (xy  1) dx = 0,  x > 0, y12=3-e. Then y1 is equal to
  1. 1
  2. e
  3. 2-e
  4. 3

Solution

Given differential equation is

x3dy+xy-1dx=0

dydx=1-xyx3

dydx=1x3-yx2

dydx+yx2=1x3

This is a linear differential equation.

If IF=e1x2dx=e-1x

Solution of a given linear differential equation is

ye-1x=e-1x1x3dx

Put -1x=tdxx2=dt

ye-1x=-e-ttdt

ye-1x=te-t+e-t+C

y=t+1+Ce1x

y=1x+1+ Ce1x

Put x=12, then 

3-e=2+1+Ce2

C=-1e

So,

y=1x+1-1ee1x

So,

y1=1+1-1=1

Asked in: JEE Main 2023 (24 Jan Shift 1)

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