Find a particular solution yp of the differential equation
The Attempt at a Solution
I'm not really sure where to start? I solve for the homogeneous solution and get C1e^ -4.26556+C2e^-.2344355629=0. I'm just not sure where to go from there. Should I do
y(x)=(Acos(x)+Bsin(x))^2 since it's just cos (x)*cos(x) or is not that right approach?