3 How to obtain the response of an LTI system described by its transfer function for an arbitrary input function?

Problem: Find the response for the continuos time system defined by the transfer function

$$H(s)=\frac{1}{s^{2}+0.2s+1}%$$

when the input is given by

$$u(t)=e^{-t}%$$

and display the response and input on the same plot.

Comment: It is easier to see the analytical form of the responses in Mathematica and Maple in the form of a formula as a function of time and not just the plot of the responses.