Definition of antinode according to google: the position of maximum displacement in a standing wave system
And displacement is a vector, so therefore, the crests would be the maximum while the troughs are the minimums.
From this, we can draw the conclusion that crests are antinodes while troughs can't be, as they're negative values.
However, the following graph shows otherwise:
Something seems to be wrong here. If both crests and troughs are antinodes, then shouldn't the definition for antinodes be 'the position of maximum DISTANCE', where minimums and maximums have the same magnitudes?
Best Answer
There is nothing wrong with the definition in terms of displacement because half a period later the graph looks like this.
So perhaps it would be better to have it as
You could also use the terms "maximum amplitude" or "maximum magnitude of the displacement".