Saya mau tau Gambaran sacara matematis dari Panyampur frékuénsi. Jelaskan dalam bahasa sunda

The input signals are, in the simplest case, sinusoidal voltage waves, representable as

where éach A is an amplitude, éach f is a frequency, and t represents time.  (In réality even such simple waves can have various phases, but that does not enter here.)  One common approach for adding and subtracting the frequencies is to multiply the two signals; using the trigonometric identity