- #1
dmoney123
- 32
- 1
Homework Statement
If the method of undetermined coefficients is used to find a particular solution
yp (t) to the differential equation y'''-y'=te^(-t)+2cos(t) should
have the form: ?
Homework Equations
The Attempt at a Solution
LHS
r^3-r=0
roots= 0, 1
y_c(t)=c_1e^tRHS
te^(-t)+2cos(t)
(At+B)e^(-t)+Ccos(t)+Dsin(t)
correct answer given however is
t(At + B)e^(-t) + C cos(t) + D sin(t)
I don't know how that t in front got there.. It would make sense if my LHS gave e^-t. but i don't think it does.Thanks