Content deleted Content added
No edit summary |
Owen Reich (talk | contribs) m Added the rad function (as in the ABC Conjecture), and added a definition for the Carmichael function. |
||
(36 intermediate revisions by 28 users not shown) | |||
Line 1:
{{
In [[mathematics]], some functions or groups of functions are important enough to deserve their own names. This is a listing of articles which explain some of these functions in more detail. There is a large theory of [[special functions]] which developed out of [[statistics]] and [[mathematical physics]]. A modern, abstract point of view contrasts large [[function space]]s, which are infinite-dimensional and within which most functions are
See also [[List of types of functions]]
Line 8:
===Algebraic functions===
[[Algebraic function]]s are functions that can be expressed as the solution of a polynomial equation with
* [[Polynomial]]s: Can be generated solely by addition, multiplication, and raising to the power of a positive integer.
** [[Constant function]]: polynomial of degree zero, graph is a horizontal straight line
** [[Linear function]]: First degree polynomial, graph is a straight line.
Line 15:
** [[Cubic function]]: Third degree polynomial.
** [[Quartic function]]: Fourth degree polynomial.
** [[
* [[Rational function]]s: A ratio of two polynomials.
* [[nth root|''n''th root]]
Line 25 ⟶ 24:
[[Transcendental function]]s are functions that are not algebraic.
* [[Exponential function]]: raises a fixed number to a variable power.
* [[Hyperbolic function]]s: formally similar to the [[trigonometric functions]].
** [[Inverse hyperbolic functions]]: [[Inverse function|inverses]] of the [[hyperbolic functions]], analogous to the [[Inverse trigonometric functions|inverse circular functions]].
* [[Logarithm]]s: the inverses of exponential functions; useful to solve equations involving exponentials.
** [[Natural logarithm]]
** [[Common logarithm]]
** [[Binary logarithm]]
* [[Exponentiation#Power functions|Power functions]]: raise a variable number to a fixed power; also known as [[Allometric function]]s; note: if the power is a rational number it is not strictly a transcendental function.
* [[Periodic function]]s
** [[Trigonometric function]]s: [[sine]], [[cosine]], [[tangent (trigonometry)|tangent]], [[cotangent]], [[secant (trigonometry)|secant]], [[cosecant]], [[exsecant]], [[excosecant]], [[versine]], [[coversine]], [[vercosine]], [[covercosine]], [[haversine]], [[hacoversine]], [[havercosine]], [[hacovercosine]], [[Inverse trigonometric functions]] etc.; used in [[geometry]] and to describe periodic phenomena. See also [[Gudermannian function]].
==
===Piecewise special functions===
{{columns-list|colwidth=20em|
* [[Indicator function]]: maps ''x'' to either 1 or 0, depending on whether or not ''x'' belongs to some subset.
Line 41 ⟶ 43:
** [[Heaviside step function]]: 0 for negative arguments and 1 for positive arguments. The integral of the [[Dirac delta function]].
* [[Sawtooth wave]]
* [[Square wave (waveform)|Square wave]]
* [[Triangle wave]]
* [[Floor function]]: Largest integer less than or equal to a given number.
* [[Ceiling function]]: Smallest integer larger than or equal to a given number.
* [[Sign function]]: Returns only the sign of a number, as +1
* [[Absolute value]]: distance to the origin (zero point)
}}
===Arithmetic functions===
{{main|Arithmetic function}}
* [[divisor function|Sigma function]]: [[Summation|Sums]] of [[Exponentiation|power]]s of [[divisor]]s of a given [[natural number]].
* [[Euler's totient function]]: Number of numbers [[coprime]] to (and not bigger than) a given one.
Line 54 ⟶ 59:
* [[Partition function (number theory)|Partition function]]: Order-independent count of ways to write a given positive integer as a sum of positive integers.
* [[Möbius function|Möbius μ function]]: Sum of the nth primitive roots of unity, it depends on the prime factorization of n.
* [[Chebyshev function]]s
* [[Von Mangoldt function]], Λ(''n'') = log ''p'' if ''n'' is a positive power of the prime ''p''▼
* [[Carmichael function]]: <math>\lambda(n)=</math> The smallest integer <math>m</math> such that <math>a^m\equiv 1\pmod{n}</math> for all <math>a</math> coprime to <math>n</math>
* [[Radical of an integer|Radical function]]: The product of the distinct prime factors of a positive integer input.
===Antiderivatives of elementary functions===
Line 59 ⟶ 70:
* [[Exponential integral]]
* [[Trigonometric integral]]: Including Sine Integral and Cosine Integral
* [[Inverse tangent integral]]
* [[Error function]]: An integral important for [[normal distribution|normal random variables]].
** [[Fresnel integral]]: related to the error function; used in [[optics]].
Line 74 ⟶ 86:
* [[Multivariate gamma function]]: A generalization of the Gamma function useful in [[multivariate statistics]].
* [[Student's t-distribution]]
* [[Gamma function#Pi function|Pi function]]
===Elliptic and related functions===
{{columns-list|colwidth=20em|
* [[Elliptic integral]]s: Arising from the path length of [[ellipse]]s; important in many applications
** [[Carlson symmetric form]]
** [[Legendre form]]
* [[Nome (mathematics)|Nome]]
* [[
* [[Elliptic function]]s: The inverses of elliptic integrals; used to model double-periodic phenomena.
**[[Jacobi's elliptic functions]]
**[[Weierstrass's elliptic functions]]
**[[Lemniscate elliptic functions]]
* [[Theta functions]]
* [[Neville theta functions]]
* [[Modular lambda function]]
* Closely related are the [[modular form]]s, which include
** [[J-invariant]]
** [[Dedekind eta function]]
}}
===Bessel and related functions===
{{columns-list|colwidth=20em|
Line 99 ⟶ 119:
* [[Laguerre polynomials]]
* [[Chebyshev polynomials]]
* [[Synchrotron function]]
}}
===Riemann zeta and related functions===
{{columns-list|colwidth=20em|
Line 114 ⟶ 136:
** [[Clausen function]]
** [[Complete Fermi–Dirac integral]], an alternate form of the polylogarithm.
** [[Dilogarithm]]
** [[Incomplete Fermi–Dirac integral]]
** [[Kummer's function]]
▲** [[Spence's function]]
* [[Riesz function]]
}}
===Hypergeometric and related functions===
* [[Hypergeometric function]]s: Versatile family of [[power series]].
Line 124 ⟶ 147:
* [[Associated Legendre functions]]
* [[Meijer G-function]]
* [[Fox H-function]]
===Iterated exponential and related functions===
Line 131 ⟶ 155:
* [[Pentation]]
* [[Super-logarithm]]s
* [[Tetration]]
===Other standard special functions===
*
▲* [[Liouville function]], λ(''n'') = (–1)<sup>Ω(''n'')</sup>
▲* [[Von Mangoldt function]], Λ(''n'') = log ''p'' if ''n'' is a positive power of the prime ''p''
* [[Lamé function]]
* [[Mathieu function]]
Line 145 ⟶ 165:
* [[Painlevé transcendents]]
* [[Parabolic cylinder function]]
▲* [[Synchrotron function]]
* [[Arithmetic–geometric mean]]
===Miscellaneous functions===
* [[Ackermann function]]: in the [[theory of computation]], a [[computable function]] that is not [[primitive recursive function|primitive recursive]].
* [[Dirac delta function]]: everywhere zero except for ''x'' = 0; total integral is 1. Not a function but a [[distribution (mathematics)|distribution]], but sometimes informally referred to as a function, particularly by physicists and engineers.
* [[Dirichlet function]]: is an [[indicator function]] that matches 1 to [[Rational number|rational numbers]] and 0 to [[Irrational number|irrationals]]. It is [[nowhere continuous]].
* [[Thomae's function]]: is a function that is continuous at all irrational numbers and discontinuous at all rational numbers. It is also a modification of Dirichlet function and sometimes called Riemann function.
* [[Kronecker delta function]]: is a function of two variables, usually integers, which is 1 if they are equal, and 0 otherwise.
* [[Minkowski's question mark function]]: Derivatives vanish on the rationals.
* [[Weierstrass function]]: is an example of [[continuous function]] that is nowhere [[Differentiable function|differentiable]]
== See also ==
* [[List of
* [[Test functions for optimization]]
* [[List of mathematical abbreviations]]
* [[List of special functions and eponyms]]
== External links ==
* [https://archive.
* [http://eqworld.ipmnet.ru/en/auxiliary/aux-specfunc.htm Special functions] at EqWorld: The World of Mathematical Equations.
[[Category:Calculus|Functions]]
[[Category:Mathematics-related lists|Functions]]
[[Category:Number theory|Functions]]
[[Category:Functions and mappings| ]]
[[pl:Funkcje elementarne]]
|