MHT CET202120 Sep 2021Evening ShiftMathematicsDifferential EquationsActual
The general solution of (x d y d x -y ) y x =x^3 e^x is
Options
- Ae ^ x ( x -1)+ y x + c =0
- Bxe ^ x + y x + c =0
- Ce ^ x ( x +1)+ y x + c =0
- Dex ^ x - y x + c =0
Correct answer
A. e ^ x ( x -1)+ y x + c =0
Step-by-step solution
aligned & (x d y d x -y ) y x =x^3 e^x & Put y x =t x d y d x -y x^2 = d t d x aligned Put y x =t x d y d x -y x^2 = d t d x Hence eq. (i) becomes aligned & x ^2 ( d t d x ) t=x^3 e^x ( d t d x ) t=x e^x & t d t= x^x d x & - t=x e^x- e^x d x=x e^4-e^x+c & - ( y x )=e^x(x-1)+c aligned