Originally Posted by

**lillybeans** Thank you both I solved this problem BUT I have another one which I am really stuck on this time, supposedly a much easier problem.

There are two questions that I am trying to solve on web assignment. The goal is to find a general form of a particular solution to each ODE. The question asks me to represent all constants in the solution using "P,Q,R,S,T..etc.", in that order.

1. y'''-9y''+14y'=x^{2}

2. y''-9y'+14y=x^{2}e^{4x}

For the first one I wrote:

yp=Px^{3}+Qx^{2}+Rx

Second one:

yp=(Px^{2}+Qx+R)e^{4x}

Neither of the answers are correct, according to the computer. Where did I go wrong?