What is the name of the part of the wave that is labeled with the question mark?https://media.edgenuity.com/contentengine/frames/2a178704-9018-11e3-966b-bc764e043e0c/3208-10-03-10-11-image1.png

What is the name of the part of the wave that is labeled with the question mark?https://media.edgenuity.com/contentengine/frames/2a178704-9018-11e3-966b-bc764e043e0c/3208-10-03-10-11-image1.png