(computing) an algorithm that generates a numeric, or fixed-size character output from a variable-sized piece of text or other data; used in database table queries, cryptography and in error-checking

(calculus) Of a function, another function, the value of which for any value of the independent variable is the instantaneous rate of change of the given function at that value of the independent variable.

(mathematical analysis) A meromorphic function which generalizes the notion of factorial to complex numbers and has singularities at the nonpositive integers; any of certain generalizations or analogues of said function, such as extend the factorial to domains other than the complex numbers.

(mathematics) A set functions that are analogues of the trigonometric functions for hyperbolic spaces. They can be derived from some arithmetic operations on the exponential function with base e and the inverse function, and was named after the corresponding similar trigonometric function.

(mathematics) a mathematical representation of the relation between the input and output of a linear time-invariant system

(mathematics) A function, the result of the division of two exponential functions, that gives rise to the logistic curve.

(physics) a mathematical function that describes the behaviour of paramagnetic materials and the dielectric properties of insulators

(mathematics) a function of the generalized coordinates and velocities of a dynamic system from which Lagrange's equations may be derived

(mathematics) The general solution of a homogenous linear differential equation.

(programming) Programming in a style that, in lieu of assignment, uses procedure calls to bind variables to values, so that referential transparency is preserved.