You make that choice for because any derivative of will have that form.
So that part was correct.
Hi I have some problem with the following d.e
y'' + 4y' + 5y = xe^x.
I will solve it as much as I can
fives yh = c1 cosx + c2 sinx)*e^-2x
hard to know what to choose, but I looked at an example
Yp = (A+Bx)e^x (I don't really know why we take it)
Yp' = (A + B + Bx)e^x
Yp'' = (A + 2b + Bx)e^x
Right lets put it into the d.e
((A + 2b + Bx)e^x) + 4((A + B + Bx)e^x) + 5((A+Bx)e^x) = x^x
I dont whats happenening but i dont get the real, constants, I get B = -1/4 etc
would be nice if someone could correct my solution, and help me