Question

What's the initial guess for y"-2y'-3y=e^(x)(cosx-2sinx)?

Answer 1

you don't have any conflict with the complementary solution which is based in \(e^{3x}\) and \(e^{-x}\) so proceed with guesses \(A e^x \cos x\) and \(B e^x \sin x\), i reckon

they'll just flip back and forward between the trig functions

Answer 2

Thank you!