Finding the solution to an IVP Problem. Basic Differential Equations problem.

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Homework Help Overview

The discussion revolves around solving an initial value problem (IVP) related to basic differential equations, specifically involving the equation ty' + 7y = 2t^2 e^(2t) with the initial condition y(1) = 7. Participants are exploring the linearity of the equation and the existence of solutions over certain intervals.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the complexity of the integration involved and question whether the original poster has made errors in their approach. There are suggestions to derive coefficients of a polynomial and to consider different methods of integration, including using integration by parts multiple times.

Discussion Status

The discussion is active, with various participants providing insights and suggestions on how to approach the integration challenge. Some guidance has been offered regarding methods of integration and the use of initial conditions, but there is no explicit consensus on a single method or solution path.

Contextual Notes

Participants are working under the constraints of a homework assignment, which may impose specific methods or formats for presenting solutions. The original poster expresses uncertainty about their work and the complexity of the integration involved.

cyturk
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I am trying to solve an IVP problem and I seem to be stuck on it because I am getting an integration that seems very complicated and I think I messed up on it, I have my work so far below.

Homework Statement



Find the solution to the IVP

ty^'+7y=2t^2 e^2t, y(1)=7

Is this equation linear? Determine in what interval the solutions exist.


Homework Equations





The Attempt at a Solution



rs1nk.jpg


The image has my work so far, as you can see the integration for (t^7)(2te^2t) is a beast and that is why I think I am wrong so far. Here is the integration answer http://www.wolframalpha.com/input/?i=integrate+%28t^7%29%282te^%282t%29%29.
 
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The primitives of (t^8)exp(2t) are on the form P(x)exp(2t) were P(x) is a 8th degree polynomial.
Derive this function and find the coefficients of the polynomial by indentification with (t^8)exp(2t)
 
You started out very well, and from:
[tex] \frac{d}{dt}(t^{7}y)=2t^{8}e^{2t}[/tex]
I think you have made an error, you can do two things: 1) You can do an indefinite integration and add an integration constant and find that constand by using the initial condition or 2) integrate from 1 to t both sides and use Y(1)=7.
 
Integrate 2t8e2t using integration by parts- 8 times!
 
HallsofIvy said:
Integrate 2t8e2t using integration by parts- 8 times!

Thanks for everyone else and this is what I ended up doing. It was the correct way of solving the problem even though it was a little bit of a hassle! :)
 

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