Find the amplitude of y = A·sin(Bx + C) + D and describe the full wave properties.
The amplitude of y = A·sin(Bx + C) + D is |A| — the distance from the midline (y = D) to the peak. The wave oscillates between D − |A| and D + |A|.
Amplitude
Amplitude = |A|
No — amplitude is always |A|, a non-negative number. A negative A flips the wave vertically but doesn't change the amplitude.
The total peak-to-trough height is 2·|A|. Amplitude is half of that — the distance from the midline to a peak.