Solving D.E. with Variation of Parameters Technique

Click For Summary

Homework Help Overview

The discussion revolves around solving a differential equation (D.E.) using the variation of parameters technique. The original poster presents the equation x^2y'' - xy' + y = x^3 and mentions the need to first solve the associated homogeneous equation.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to solve the homogeneous part of the D.E. and expresses uncertainty about how to proceed after obtaining a particular solution involving C_2tx. Some participants suggest that the equation is an Euler equation and recommend a transformation to simplify it.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the equation. Some guidance has been offered regarding the nature of the equation and potential substitutions, but no consensus has been reached on the next steps.

Contextual Notes

The original poster is required to use the variation of parameters technique, and there is a mention of needing to transform the equation into a linear form with constant coefficients. The nature of the equation as an Euler equation is also under discussion.

RadiationX
Messages
255
Reaction score
0
I need to solve this D.E.

[tex]x^2y''-xy' + y = x^3[/tex]

i'm supposed to use the variation of parameters technique.

in that technique i need to get a coeffecient of 1 in the first postion of y'' and then sove the homogenous D.E.

[tex]y''-\frac{y'}{x} +\frac{y}{x^2}=0[/tex]

the above leads to

[tex]m^2-2m +1=0[/tex]

now solving this i get

[tex]C_1x +C_2tx[/tex]

my problem is that i don't know how to move forward with
[tex]C_2tx[/tex]

how do i proceed
 
Last edited:
Physics news on Phys.org
It's an Euler equation.You need to transform it into a linear equation with constant coeffs.Read the theory again and identify the substitution you need.

Daniel.
 
do you mean that this is a Bernoulli equation?
 
I told u it was/is an Euler eqn.

Make the sub

[tex]x=e^{t}[/tex]

[tex]y(x)\longrightarrow \bar{y}(t)[/tex]

Daniel.
 
Last edited:
ok. i'll figure it out
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
Replies
9
Views
3K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 22 ·
Replies
22
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
4
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K
Replies
19
Views
3K
Replies
1
Views
2K