How do I solve this?

Consider the RCL circuit in the figure, with a sinusoidal voltage source with frequency f, and amplitude 100V. (a) (2) What is the effective impedance of the circuit as a function of f? (c) (2) At what frequency f is the current maximal? (b) (3) What is the amplitude of the current in the circuit at the frequency you found in (c), and what is it at half that frequency? (d) (3) In an instant when the cm'rent through the inductor is maximized (at the maximal frequency you found in (c) ), the capacitor and voltage source are shortcircuited (the blue switch in the figure is closed). Denote that time as IZD. What is the current through the inductor as a function of time? At what time is the current lfe3 of its maximal value? SHALL L t (m H