Superposition of Two Sine Waves with Sum and Beats

This Demonstration shows the sum and the envelope of the beat for two sine waves. You can change the frequencies of either wave or modulate the amplitude or phase of the second wave.

The buttons A, B, C, …, L are presets. They show some typical situations that may be freely used for further investigations. The notebook being quite complex with all its possibilities, the presets illustrate how it is possible to reduces redundancies by switching off some waves or the filling. Stepping through the presets while analyzing the parameters and the obtained results lets you see the most interesting cases of adding two sine waves.