If the waveform shown in Figure P4.11 is the voltage across a capacitor plotted as a function of time with:
$$
v_{\mathrm{PK}}=20 \mathrm{~V} \quad T=40 \mu \mathrm{~s} \quad C=680 \mathrm{nF}
$$
determine and plot the waveform for the current through the capacitor as a function of time.