- #1

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## Homework Statement

y''-2y'-3y=-3t*e^(-t)

## Homework Equations

Has to be done with method of undetermined coefficients

## The Attempt at a Solution

the chacteristic equation is: c1*e^(3t) + c2*e^(-t)

my attempt at Yp is (a*t+b)*e^(-t)... so ya thats not it. i tried many versions and i keep on getting a = 3t/4.

the book has the answer as y=c1*e^(3t) + c2*e^(-t)+(3/16)*t*e^(-t)+(3/8)*t^2*e^(-t)