In computing, NaN (/næn/), standing for Not a Number, is a member of a numeric data type that can be interpreted as a value that is undefined or unrepresentable, especially in floating-point arithmetic. Systematic use of NaNs was introduced by the IEEE 754 floating-point standard in 1985, along with the representation of other non-finite quantities such as infinities.
In mathematics, zero divided by zero is undefined[a] and is therefore represented by NaN in computing systems. The square root of...
