Function (nonfiction)

A function f takes an input x, and returns a single output f(x). One metaphor describes the function as a "machine" or "black box" that for each input returns a corresponding output.

In mathematics, a function is a relation between a set of inputs and a set of permissible outputs with the property that each input is related to exactly one output.

An example is the function that relates each real number x to its square x2.

The output of a function f corresponding to an input x is denoted by f(x) (read "f of x").

In this example, if the input is −3, then the output is 9, and we may write f(−3) = 9.

Likewise, if the input is 3, then the output is also 9, and we may write f(3) = 9. (The same output may be produced by more than one input, but each input gives only one output.)

In the News

• 

  Supervillains Forbidden Ratio and Gnotilus form crime team to destroy the Golden ratio.

• 

  Halting problem is delicious, says supervillain Forbidden Ratio.

• 

  Asclepius Myrmidon finds Halting problem, forecasts multiple casualties from Pi disaster.

Fiction cross-reference

• Asclepius Myrmidon
• Crimes against mathematical constants
• Gnomon algorithm
• Gnomon Chronicles
• Forbidden Ratio - a mathematical function and supervillain.
• Killer Poke - a software defect for hire, and contract killer for Murder, Incorporated 1.1.
• Pi disaster

Nonfiction cross-reference

• Algebraic function (nonfiction) - a function that can be defined as the root of a polynomial equation. Quite often algebraic functions are algebraic expressions using a finite number of terms, involving only the algebraic operations addition, subtraction, multiplication, division, and raising to a fractional power.
• Algorithm (nonfiction)
• Complex-valued function (nonfiction) - a function whose values are complex numbers. Not to be confused with complex variable function: the domain of a complex-valued function does not necessarily have any structure related to complex numbers.
• Functional equation (nonfiction) - any equation in which the unknown represents a function. Often, the equation relates the value of a function (or functions) at some point with its values at other points.
• Golden ratio (nonfiction)
• Holomorphic function (nonfiction) - a complex-valued function of one or more complex variables that is, at every point of its domain, complex differentiable in a neighborhood of the point.
• Mathematics (nonfiction)

External links:

• Function (mathematics) @ Wikipedia