6y''+y'-y=x^2-x+4e^(-3t)

"find a particular solution"

I get

-4*e^(-3t)-t^2-t-13

or

39/50*e^(-3t)-t^2-t-13

but apparently they both are wrong?

Can someone here help me confirm if they are right or wrong?

EDIT: I'm an idiot.

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- October 17th 2011, 05:08 PMstupidoldmanDifferencial equation problem?
6y''+y'-y=x^2-x+4e^(-3t)

"find a particular solution"

I get

-4*e^(-3t)-t^2-t-13

or

39/50*e^(-3t)-t^2-t-13

but apparently they both are wrong?

Can someone here help me confirm if they are right or wrong?

EDIT: I'm an idiot. - October 17th 2011, 05:33 PMAckbeetRe: Differencial equation problem?
Several comments:

0. You are mixing independent variables there. Are they all x's? Or all t's?

1. Checking to see if your guess works is usually fairly straight-forward. Just plug your solution into the DE and see if it satisfies it.

2. Assuming your RHS is all x's, I would try a particular solution of the form y_p = A x^2 + B x + C + D exp(-3x).

3. Finally, you spell it "differential", not "differencial".