Curves that can be used in physics for analysing pairs of simple harmonic motions are generally known as Lissajous Curves. They describe the superposition of two oscillations taking place at the right angle to each other, at different frequencies. Their main application can be found in oscilloscopes. These instruments allow observation of two superimposed sine waves coming from varying signal voltages of sinusoidal nature. Depending on the frequency and amplitude of each wave, and the phase between them, we can see interesting patterns emerging.

Because the superimposed two perpendicular oscillations can be described with parametric equations for x and y in the Cartesian coordinate system, we can quite easily demonstrate the resulting shapes graphically using Excel charts. Let's look first at some of "oscilloscopic" patterns generated with Excel.