$4\mathrm{.}17$ The current source in the circuit of Fig. P$4\mathrm{.}17$ is given by $i_s(t)=6e^{-2t}u(t)A.$ Determine $i_L(t)$ for $t0$ given that $R_1=10,R_2=5,L=0\mathrm{.}6196H,$ and $LC=\frac{1}{15}s.$

Figure r$4\mathrm{.}1/$: Vircuit Ior Prodiems $4\mathrm{.}1/$ and $4\mathrm{.}16.$