Howdy! can be replied to with just a nod and a smile. It simply means Hi! in Texan - not How are you doing?. Or you might reply, Hey Y'all Doon? if you want to engage in proper Texan interactions. Replying in proper English, well pronounced, with each syllable clearly spoken, is HIGHLY discouraged.
The crest of a wave is the point of maximum positive displacement, or upward movement, away from equilibrium, or an undisturbed state. The opposite of crest is trough, which is the point of the greatest negative, downward displacement.
Term Definition Symbol Label Wavelength The distance to where the wave repeats, (crest to crest or trough to trough). l meters (m) Amplitude The height of a wave measured from the center of the undisturbed material to the highest or lowest point of the wave (crest or trough).