General Solution to Linear, Homogenius, Second-Order Differential Equation

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Discussion Overview

The discussion revolves around solving a specific second-order linear homogeneous differential equation, with participants exploring various methods and approaches to tackle the problem. The scope includes mathematical reasoning and technical explanations related to differential equations.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant presents the differential equation and expresses uncertainty about how to proceed after transforming it into a specific form.
  • Another participant suggests consulting a differential equations textbook and mentions potential substitution methods to simplify the equation, noting their own unsuccessful attempts.
  • This participant also proposes using Mathematica for a solution, indicating that it was unable to solve the equation, and suggests power series as a possible method for an analytical solution.
  • A different participant questions the classification of the ODE as homogeneous and suggests that direct integration leads to a first-order ODE, implying a different approach may be needed.

Areas of Agreement / Disagreement

Participants do not appear to reach a consensus on the classification of the differential equation or the most effective method for solving it. Multiple competing views and approaches remain present in the discussion.

Contextual Notes

There are unresolved assumptions regarding the nature of the differential equation and the effectiveness of the proposed methods. The discussion includes references to specific mathematical techniques without fully establishing their applicability to the problem at hand.

nivekious
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I need to solve d/dx(e^(-(x^2))*(du/dx))=u+x*(du/dx)
I get e^(-(x^2))*u''-2xe^(-(x^2))*u'=u+x*u'
u''-2x*u'=e^(x^2)*u+xe^(x^2)*u'
u''+(2x-xe^(x^2))*u'-e^(x^2)*u=0
but I have no idea how to approach the problem from here. Can somebody please help?
 
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nivekious said:
I need to solve d/dx(e^(-(x^2))*(du/dx))=u+x*(du/dx)
I get e^(-(x^2))*u''-2xe^(-(x^2))*u'=u+x*u'
u''-2x*u'=e^(x^2)*u+xe^(x^2)*u'
u''+(2x-xe^(x^2))*u'-e^(x^2)*u=0
but I have no idea how to approach the problem from here. Can somebody please help?

I can suggest a route to study it. First, get a DE text that deals with second-order DEs with variable coefficients. I use "Intermediate Differential Equations" by Rainville. There are some simple substitutions to try with these types of equations, putting it in it's normal form [itex]v''+Iv=0[/itex] and sometimes that results in a constant-coefficient equation. Some other substitution method to get a constant-coefficient equation. I tried those quickly and did not seem to do it. But you may want to try yourself. My next step would be to turn to Mathematica in desperation using the DSolve command. I tried that and Mathematica can't solve it. My next step, even more desperate but not too uncommon is to use power series which of course in this case will involve Cauchy-products but that's ok according to Rainville. If I had to solve it analytically, and I could think of nothing else, I'd do it with power series.
 
General Solution to Linear, Homogenius, Second-Order Differential Equation
I don't think that the ODE is on the homogenius kind. It doesn't matter since direct integration directly leads to a first order ODE :
 

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. . . schooled. Very nice though. :)
 

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