Let y = y x be the solution curve of the differential equation d y d x = y x 1 + x 2 1 + log e x , x > 0…

Let y=yx  be the solution curve of the differential equation dydx=yx1+x21+logex, x>0,y(1)=3. Then y2(x)9 is equal to :
  1. x25-2x32+logex3
  2. x22x32+logex3-3
  3. x23x31+logex2-2
  4. x27-3x32+logex2

Solution

Given differential equation can be rewritten as,

dydx-yx=y31+logex

1y3dydx-1xy2=1+logex

Let -1y2=t2y3dydx=dtdx

dt2dx+tx=1+logex

dtdx+2tx=21+logex ..........(1)

We know the solution of the differential equation dydx+Py=Q is given by,

yePdx=QePdx+C  (Where I.F.=ePdx)

Therefore, on solving equation(1) we get,

I.F.=e2xdx=x2

-x2y2=231+logexx3-x33+C ......(2)

Given,y(1)=3

19=-213-19+C

 C=59

Now putting value of C in equation(2) we get,

y29=x25-2x32+logex3

Asked in: JEE Main 2023 (25 Jan Shift 1)

Practice more Differential Equations questions on Aicharya