25.6.1 Amplitude A: How Tall the Wave Is
Core ideaA acts like a volume knob, stretching the wave up or squashing it down and setting how far it can stray from the midline.
Module goal. We treat a sine wave's amplitude, period, and phase as adjustable dials, understand how each parameter reshapes the graph, and use it to describe real back-and-forth motions like springs and sound.