1. The problem statement, all variables and given/known data Find a particular solution of y"+2y'+y=8x^2*cosx-4xsinx. The answer is yp=-(14-10x)cosx-(2+8x-4x^2)sinx. 2. Relevant equations None. 3. The attempt at a solution r^2+2r+1=0 (r+1)^2=0 r=-1, -1 y=Axe^(-x)+Be^(-x) So what should the initial guess yp be for this problem? How to find the initial guess yp?