The problem I am having is coming up with the differential equation that describes the current through the inductor. I know that for a capacitor and a Thevinan equivalent circuit I would simply use kvl and then do some substitutions. However, for this Norton equivalent circuit with and inductor, I cannot seem to figure out how to come up with an equation describing Il2 (as labled). I tried kcl at the top node(Vx): -In +3/Vx + Il2 = 0 but then I couldn't describe the voltage Vx. I also tried two current loops, first loop: 3(In - Il2) = 0, second loop: 3(Il2 - In) = 0. However that seems to suggest that Il2 = In which does not seem right. Can someone tell me where I went wrong or what I need to do after this step if I have done everything correctly so far?