What could be the best guess of the general form of the particular solution yp (t) of the following non-homogeneous equation y" - 6y+9y= et using the method of undetermined coefficients by inspecting the homogeneous solution yn (t)? Do not attempt to find yp (t) explicitly. Yp (t) = Aet Yp (t) = Atet Yp (t) = At et Yp (t) = At t O None of the above