Finding Particular Solutions for Second Order Linear Differential Equations

[strawberrysk8]

Homework Statement

Find particular solution for
y''+2y'+5y = 4(e^-t)cos2t

Homework Equations

y.c = C(e^-t)cos2t + C(e^-t)sin2t

The Attempt at a Solution

y.p (particular solution) = At(e^-t)cos2t + Bt(e^-t)sin2t does not work! Help please!

 

[gabbagabbahey]

Are you sure your $y_p$ doesn't work? Why don't you show us what you're getting when you plug it into the ODE.

 

[strawberrysk8]

reply oh i figured it out. thank you!