function

In computing, a small part of a program that supplies a specific value – for example, the square root of a specified number, or the current date. Most programming languages incorporate a number of built-in functions; some allow programmers to write their own. A function may have one or more arguments (the values on which the function operates). A function key on a keyboard is one that, when pressed, performs a designated task, such as ending a program.

function

In mathematics, a function f is a non-empty set of ordered pairs (x, f(x)) of which no two can have the same first element. Hence, if f(x) = x² two ordered pairs are (−2,4) and (2,4). The set of all first elements in a function's ordered pairs is called the domain; the set of all second elements is the range. Functions are used in all branches of mathematics, physics, and science generally. For example, in the equation y = 2x + 1, y is a function of the symbol x. This can be written as y = f(x).

In another example, the formula t = 2π√(l/g) shows that for a simple pendulum, the time of swing t is a function of its length l and of no other variable quantity (π and g, the acceleration due to gravity, are constants).

function

In business, role of an individual within an organization. Functions are divided into broad categories such as marketing, finance, and human resources. Not all organizations are structured by function. They are structured using other means, such as by brand or by product.