Original sentence: A crest is the point on a wave with the greatest positive value or upward displacement in a cycle.A trough is the opposite of a crest.When 180° out of phase the result is destructive interference: the resulting wave is the undisturbed line having zero amplitude.When the crests and troughs of two waves of equal magnitude and frequency intersect or collide when in phase with each other the result is called constructive interference and the magnitudes double (above and below the line)
Edited sentence: , 704 pages.A crest is the point on a wave with the maximum value or upward displacement within a cycle.A trough is the opposite of a crest, so the minimum or lowest point in a cycle.When in antiphase – 180° out of phase – the result is destructive interference: the resulting wave is the undisturbed line having zero amplitude.When the crests and troughs of two waves of equal amplitude and frequency intersect or collide, while being in phase with each other, the result is called constructive interference and the magnitudes double (above and below the line)