3. Given the differential equation below, find the solution using Laplace transformation. The parameters R, L,
and I<sub>s</sub> are constants that are related to the resistance and the inductance in an RL circuit, and current I<sub>s</sub>
is applied at time t = 0 to the circuit in series. I<sub>L</sub> is the function you have to solve for and it corresponds
to the current in the inductor. Initially I<sub>L</sub>(0) = 0.
$L \frac{dI_L}{dt} + RI_L(t) = RI_s$
(a) Give an expression for I<sub>L</sub>(s), where \mathcal{L}{I_L(t)} = I<sub>L</sub>(s),
(b) Give an expression for I<sub>L</sub>(t); the solution to the differential equation