Nu (letter)

Nu (uppercase/lowercase Ν ν) is a letter of the Greek alphabet used to represent the "n" sound in Ancient and Modern Greek. In the system of Greek numerals, it has a value of 50. Letters that came from it include the Roman N and Cyrillic Н.
In statistics, the lowercase formula_1 can be used to represent degrees of freedom. In physics, the same letter can also used to represent kinematic viscosity and the frequency of a wave.