This is a second$-$order circuit. There is an initial voltage on the capacitor $($assuming clockwise current$)$ v$(0)=+12$ V$,$ and an initial current in the inductor iL$(0)=30$ mA clockwise. In order

to solve the differential equation for i$($t$),$ the initial voltages vL$(0+)$

and vR$(0+),$ and di$($t$)/$dt$|$t$=0+$ must

be found. Using what you know about inductors, capacitors, and KCL$,$ find these values