Wavelength denotes the time for one cycle of a periodic process
Abcdefg
There cannot be more than two because there are only two vowels, e and a. But it has to be 4 lettered, which limits a lot of option, so there can only be one 4-letter code.
The function's input value is 2.
f(x) = 2x² + 3x + 5
f(x) = 2(2)² + 3(2) + 5
f(x) = 2(4) + 6 + 5
f(x) = 8 + 11
f(x) = 19