A circuit has two terminals on the left which are labeled input. the upper terminal connects to one end of a capacitor which is labeled C. The far end of the capacitor goes to the top end of a resistor labeled R. The bottom end of the resistor goes to the common line. The lower terminal on the left also goes to the
common line. There are two terminals on the right labeled output. The top terminal goes to the junction of the capacitor and resistor. The bottom terminal goes to the common line. To the left of the circuit is a graph of a sine wave. It is about 3 times it's own height above the zero axis. This wave is indicated as the input wave for the circuit. On the right is the graph of a sine wave which is symmetrical about the zero axis. This is the output wave from the circuit.