What is laplace transform of
exp(-at)u(-t)
and if laplace of x(t) is 1/s then laplace of dx(t)/dt will be...
If the function is $\displaystyle f(t)=e^{- a t}\ u(-t)$ then fot $\displaystyle t>0$ is $\displaystyle f(t)=0$, so that its single side Laplace Tranform is...
$\displaystyle \int_{0}^{+ \infty} f(t)\ e^{- s t} dt =0$
Marry Christmas from Serbia
$\displaystyle \chi$ $\displaystyle \sigma$