In one complete cycle of a wave, there is typically one amplitude.
The amplitude of a wave represents the maximum displacement or magnitude of the oscillation from its equilibrium position. In a typical sinusoidal wave, such as a sine wave or a cosine wave, one complete cycle consists of a full oscillation from one extreme to the other and back to the starting point. During this cycle, the wave reaches its maximum positive amplitude, then crosses the equilibrium position, reaches its maximum negative amplitude, and finally returns to the equilibrium position.
Therefore, in one complete cycle, there is one maximum positive amplitude and one maximum negative amplitude, resulting in a total of one amplitude.