Question about differential equations(nonhomogenous)?

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Homework Help Overview

The discussion revolves around a nonhomogeneous differential equation of the form -2y'' + y' + y = 2t^2 - 2t - 5e^(-2t). Participants are examining the appropriate setup for a particular solution.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • The original poster suggests a particular solution of the form Ae^(-2t) + Bt^2 + Ct + D. Some participants question the validity of this setup based on the solutions to the corresponding homogeneous equation.

Discussion Status

The discussion includes an inquiry into the roots of the homogeneous equation, with one participant providing the roots as -0.5 and 1. There is a moment of reconsideration from the original poster, indicating a potential shift in confidence regarding their initial setup.

Contextual Notes

Participants are considering the implications of the roots of the characteristic equation on the form of the particular solution, particularly in relation to the nonhomogeneous terms present in the equation.

hard_assteel
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For this nonhomogeneous differential equation:

-2y''+y'+y=2t^2-2t-5e^(-2t)

would the setup for the particular solution (yp) be;
Ae^(-2t)+Bt^2+Ct+D?

Thank You
 
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It depends on the solutions to the homogeneous problem.

What are the solutions to -2y'' + y' +y = 0?

Or, equivalently, 2y'' - y' - y = 0?

If the roots of the characteristic equation for the homogeneous equation aren't r = 0 or r = -2, then, yes, that's what you want for your particular solution.
 
the roots are -.5 and 1
 
Edit, nevermind I think its fine
 

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