In a parallel \(R L C\) circuit, the state variable responses are 

\[
\begin{aligned}
v_{\mathrm{R}}(t) & =e^{-100 t}[5 \cos (300 t)+15 \sin (300 t)] \mathrm{V}, t \geq 0 \\
i_{\mathrm{L}}(t) & =20-25 e^{-100 t} \cos (300 t) \mathrm{mA}, t \geq 0
\end{aligned}
\]

Find \(R, L, C\), and \(\zeta\).