Given the transfer function,

$\frac{Y(s)}{x(s)}=2(\frac{1}{s^3+2s^2+9s+18})$

$($a$)$ Derive $y(t)$ with respect to an impulse input.

$($b$)$ Derive $y(t)$ with respect to a unit$-$step input.

$($c$)$ What are the values of $y(t)$ at $t=0$ and $t=$ with respect to a unit$-$step input?