An inductor \(L\) is connected across the secondary of an ideal transformer whose turns ratio is \(1: n\).

(a) Derive an expression for the equivalent inductance \(L_{\mathrm{EQ}}\) seen looking into the primary winding.

(b) Suppose you added a capacitor in parallel with the inductor. At what frequency would \(Z_{\mathrm{IN}}=\infty\) ?