The question was:

Solve y'' + 2y' + 5y = 2xe^(-x)cos(2x)

Using undetermined coefficients, I found the particular solution to be:

(1/4)(x^2)(e^(-x))sin(2x) + (1/8)x(e^(-x))cos(2x)

Unfortunately, there was a lot of algebra I could've easily messed up on. Is there anything online I could use to check my answer?

Thanks in advance.