part A
$ e^{st}\rightarrow h(t)\rightarrow H(S)e^{st} $
$ H(s) = \int_{-\infty}^\infty h(t)e^{-st}dt $
assume
$ h(t) = 5u(t-3) $
$ H(s) = 5\int_3^\infty e^{-st}dt $
$ H(s) = \frac{-5}{s} $
$ 4 to \infty $
$ H(s)= \frac {5}{s} $
part B
$ h(t) = \sum_{-\infty} ^\infty a_k H(s) $
since I got
$ a_1 = \frac{3}{j} $
$ a_2= \frac{-3}{j} $
$ a_3 = 2 $
$ a_4 = 2 $
