Special function/Catalogs/Catalog: Difference between revisions

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{{subpages}}
[[Special function]]s are mathematical [[function (mathematics)|function]]s that turn up so often that they have been named. This page lists the most common special functions by category, along with some of the properties that are important to functions belonging to each category. It must be stressed that there is no single way to categorize functions; any practical classification will contain overlapping categories.
[[Special function]]s are mathematical [[function (mathematics)|function]]s that turn up so often that they have been named. This page lists the most common special functions by category, along with some of the properties that are important to functions belonging to each category. It must be stressed that there is no single way to categorize functions; any practical classification will contain overlapping categories.


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|<math>\exp(x)</math>, <math>e^x</math>
|<math>\exp(x)</math>, <math>e^x</math>
|-
|-
|[[Natural logarithm]]
|[[Logarithm|Natural logarithm]]
|<math>\log(x)</math>, <math>\ln(x)</math>
|<math>\log(x)</math>, <math>\ln(x)</math>
|}
|}


===Trigonometric functions===
[[Trigonometric function]]s:
{| class="wikitable"
{| class="wikitable" style="margin-top:0"
!Name
!Name
!Notation
!Notation
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|}
|}


===Hyperbolic functions===
[[Hyperbolic function]]s:
{| class="wikitable"
{| class="wikitable" style="margin-top:0"
!Name
!Name
!Notation
!Notation
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|-
|-
|[[Hyperbolic cosecant]]
|[[Hyperbolic cosecant]]
|<math>\operatorname{csch}(x)</math>
|<math>\mathrm{csch}(x)</math>
|<math>2/(e^{x}-e^{-x})</math>
|<math>2/(e^{x}-e^{-x})</math>
|-
|-
|[[Hyperbolic secant]]
|[[Hyperbolic secant]]
|<math>\operatorname{sech}(x)</math>
|<math>\mathrm{sech}(x)</math>
|<math>2/(e^{x}+e^{-x})</math>
|<math>2/(e^{x}+e^{-x})</math>
|-
|-
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|}
|}


===Inverse trigonometric functions===
[[Inverse trigonometric function]]s:
{| class="wikitable" style="margin-top:0"
!Name
!Notation
!Triangle formula
!Exponential formula
|-
|[[Arcsine]]
|<math>\arcsin(x)</math>
|
|
|-
|[[Arccosine]]
|<math>\arccos(x)</math>
|
|
|-
|[[Arctangent]]
|<math>\arctan(x)</math>
|
|
|-
|[[Arccosecant]]
|<math>\arccsc(x)</math>
|
|
|-
|[[Arcsecant]]
|<math>\arcsec(x)</math>
|
|
|-
|[[Arccotangent]]
|<math>\arccot(x)</math>
|
|
|}
 


===Inverse hyperbolic functions===
[[Inverse hyperbolic function]]s:
{| class="wikitable"
{| class="wikitable" style="margin-top:0"
!Name
!Name
!Notation
!Notation
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|-
|-
|[[Inverse hyperbolic sine]]
|[[Inverse hyperbolic sine]]
|<math>\operatorname{arcsinh}(x)</math>
|<math>\mathrm{arcsinh}(x)</math>
|<math>\ln{x+\sqrt{x^2+1}}</math>
|<math>\ln{(x+\sqrt{x^2+1)}}</math>
|-
|-
|[[Inverse hyperbolic cosine]]
|[[Inverse hyperbolic cosine]]
|<math>\operatorname{arccosh}(x)</math>
|<math>\mathrm{arccosh}(x)</math>
|<math>\ln{x+\sqrt{x^2-1}}</math>
|<math>\ln{(x+\sqrt{x^2-1})}</math>
|-
|-
|[[Inverse hyperbolic tangent]]
|[[Inverse hyperbolic tangent]]
|<math>\operatorname{arctanh}(x)</math>
|<math>\mathrm{arctanh}(x)</math>
|<math>\frac{1}{2}\ln{\frac{1+x}{1-x}}</math>
|<math>\frac{1}{2}\ln{\frac{1+x}{1-x}}</math>
|-
|-
|[[Inverse hyperbolic cosecant]]
|[[Inverse hyperbolic cosecant]]
|<math>\operatorname{arccsch}(x)</math>
|<math>\mathrm{arccsch}(x)</math>
|
|
|-
|-
|[[Inverse hyperbolic secant]]
|[[Inverse hyperbolic secant]]
|<math>\operatorname{arcsech}(x)</math>
|<math>\mathrm{arcsech}(x)</math>
|
|
|-
|-
|[[Inverse hyperbolic cotangent]]
|[[Inverse hyperbolic cotangent]]
|<math>\operatorname{arccoth}(x)</math>
|<math>\mathrm{arccoth}(x)</math>
|
|
|}
|}


===Other===
Other:
* [[Sinc function]]
* [[Lambert W-function]]
* [[Lambert W-function]]


==Nonelementary integrals==
==Exponential integral related==
* [[Exponential integral]]
 
* [[Logarithmic integral]]
{| class="wikitable"
* [[Trigonometric integral]]s
!Function
** [[Sine integral]]
!Notation
** [[Cosine integral]]
!Definition
** [[Hyperbolic sine integral]]
|-
** [[Hyperbolic cosine integral]]
|[[Exponential integral]]
|<math>\mathrm{Ei}(x)</math>
|<math>\textstyle -\int_{-x}^{\infty} \frac{e^{-t}}{t} \, dt</math>
|-
|[[Logarithmic integral]]
|<math>\mathrm{li}(x)</math>
|<math>\textstyle \int_0^x \frac{1}{\ln t} \, dt</math>
|}
 
[[Trigonometric integral]]s:
 
{| class="wikitable"
!Function
!Notation
!Definition
|-
|[[Sine integral]]
|<math>\mathrm{Si}(x)</math>
|<math>\textstyle \int_0^x \frac{\sin t}{t} \, dt</math>
|-
|[[Hyperbolic sine integral]]
|<math>\mathrm{Shi}(x)</math>
|<math>\textstyle \int_0^x \frac{\sinh t}{t} \, dt</math>
|-
|[[Cosine integral]]
|<math>\mathrm{Ci}(x)</math>
|<math>\textstyle \gamma + \ln x + \int_0^x \frac{\cos t - 1}{t} \, dt</math>
|-
|[[Hyperbolic cosine integral]]
|<math>\mathrm{Chi}(x)</math>
|<math>\textstyle \gamma + \ln x + \int_0^x \frac{\cosh t - 1}{t} \, dt</math>
|}
 
Note: <math>\gamma</math> is [[Euler's constant]]
 
Related to the [[normal distribution]]:
 
{| class="wikitable"
!Name
!Notation
!Definition
|-
|[[Gaussian function]]
|none standardized
|<math>f(x) = a e^{-(x-b)^2/c^2}</math>
|-
|[[Error function]]
|<math>\mathrm{erf}(x)</math>
|<math>\textstyle \frac{2}{\sqrt{\pi}}\int_0^x e^{-t^2} dt</math>
|-
|[[Complementary error function]]
|<math>\mathrm{erfc}(x)</math>
|<math>1-\mathrm{erf}(x)</math>
|}
 
See also gamma related functions below; in particular, the incomplete gamma functions.


==Bessel function related==
==Bessel function related==
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|<math>-1,1</math>
|<math>-1,1</math>
|<math>1</math>
|<math>1</math>
|
|<math>1</math>, <math>x</math>, <math>{\textstyle \frac{1}{2}}</math><math>(3x^2-1)</math>, <math>{\textstyle \frac{1}{2}}</math><math>(5x^3-3x)</math>, &hellip;
|-
|-
|[[Hermite polynomials|Hermite]]
|[[Hermite polynomials|Hermite]]
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|<math>1 \cdot 3 \cdot 5 \cdots x \;\;(x \; \mathrm{odd})</math><br/>
|<math>1 \cdot 3 \cdot 5 \cdots x \;\;(x \; \mathrm{odd})</math><br/>
<math>2 \cdot 4 \cdot 6 \cdots x \;\;(x \; \mathrm{even})</math>
<math>2 \cdot 4 \cdot 6 \cdots x \;\;(x \; \mathrm{even})</math>
|<math>\begin{matrix}\frac{1}{\sqrt{\pi}}\end{matrix} \; 2^{(x+1)/2} \; \Gamma(x/2+1)</math>
|<math>\frac{\Gamma(x+1)}{2^\frac{x-1}2 *\Gamma(\frac{x+1}2)}\;\;(x \; \mathrm{odd})</math>
<br/><math>2^\frac{x-1}2 * \Gamma(\frac{x+1}2) \;\;(x \; \mathrm{even}) </math>
|-
|-
|[[Binomial coefficient]]
|[[Binomial coefficient]]
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* [[Hypergeometric function]]s
* [[Hypergeometric function]]s
* [[Meijer G-function]]
* [[Meijer G-function]]
==See also==
* [[Catalog of mathematical constants]]
* [[Catalog of probability distributions]]
* [[Catalog of number sequences]]
[[Category:CZ Live]]
[[Category:Mathematics Workgroup]]

Latest revision as of 14:58, 8 December 2009


Special functions are mathematical functions that turn up so often that they have been named. This page lists the most common special functions by category, along with some of the properties that are important to functions belonging to each category. It must be stressed that there is no single way to categorize functions; any practical classification will contain overlapping categories.

Algebraic functions

Complex parts

Elementary transcendental functions

Name Notation
Exponential function Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \exp(x)} , Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle e^x}
Natural logarithm Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \log(x)} , Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \ln(x)}

Trigonometric functions:

Name Notation Triangle formula Exponential formula
Sine Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \sin(x)} Opposite / Hypotenuse Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle (e^{ix}-e^{-ix})/2i}
Cosine Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \cos(x)} Adjacent / Hypotenuse Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle (e^{ix}+e^{-ix})/2}
Tangent Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \tan(x)} Opposite / Adjacent Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle -\mathit{i}(e^{\mathit{i}x}-e^{-\mathit{i}x})/(e^{\mathit{i}x}+e^{-\mathit{i}x})}
Cosecant Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \csc(x)} Hypotenuse / Opposite
Secant Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \sec(x)} Hypotenuse / Adjacent
Cotangent Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \cot(x)} Adjacent / Opposite

Hyperbolic functions:

Name Notation Exponential formula
Hyperbolic sine Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \sinh(x)}
Hyperbolic cosine Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \cosh(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle (e^{x}+e^{-x})/2}
Hyperbolic tangent Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \tanh(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle (e^{x}-e^{-x})/(e^{x}+e^{-x})}
Hyperbolic cosecant Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{csch}(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle 2/(e^{x}-e^{-x})}
Hyperbolic secant Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{sech}(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle 2/(e^{x}+e^{-x})}
Hyperbolic cotangent Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \coth(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle (e^{x}+e^{-x})/(e^{x}-e^{-x})}

Inverse trigonometric functions:

Name Notation Triangle formula Exponential formula
Arcsine Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \arcsin(x)}
Arccosine Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \arccos(x)}
Arctangent Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \arctan(x)}
Arccosecant Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \arccsc(x)}
Arcsecant Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \arcsec(x)}
Arccotangent Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \arccot(x)}


Inverse hyperbolic functions:

Name Notation Logarithmic formula
Inverse hyperbolic sine Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{arcsinh}(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \ln{(x+\sqrt{x^2+1)}}}
Inverse hyperbolic cosine Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{arccosh}(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \ln{(x+\sqrt{x^2-1})}}
Inverse hyperbolic tangent Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{arctanh}(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \frac{1}{2}\ln{\frac{1+x}{1-x}}}
Inverse hyperbolic cosecant Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{arccsch}(x)}
Inverse hyperbolic secant Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{arcsech}(x)}
Inverse hyperbolic cotangent Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{arccoth}(x)}

Other:

Exponential integral related

Function Notation Definition
Exponential integral Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{Ei}(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \textstyle -\int_{-x}^{\infty} \frac{e^{-t}}{t} \, dt}
Logarithmic integral Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{li}(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \textstyle \int_0^x \frac{1}{\ln t} \, dt}

Trigonometric integrals:

Function Notation Definition
Sine integral Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{Si}(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \textstyle \int_0^x \frac{\sin t}{t} \, dt}
Hyperbolic sine integral Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{Shi}(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \textstyle \int_0^x \frac{\sinh t}{t} \, dt}
Cosine integral Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{Ci}(x)} Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \textstyle \gamma + \ln x + \int_0^x \frac{\cos t - 1}{t} \, dt}
Hyperbolic cosine integral

Note: is Euler's constant

Related to the normal distribution:

Name Notation Definition
Gaussian function none standardized
Error function
Complementary error function

See also gamma related functions below; in particular, the incomplete gamma functions.

Bessel function related

Elliptic integrals

Orthogonal polynomials

See catalog of orthogonal polynomials for a more detailed listing.

Name Notation Interval Weight function , , , , ...
Chebyshev (first kind) , , , , ...
Chebyshev (second kind) , , , , ...
Legendre , , , , …
Hermite
Laguerre
Associated Laguerre

Factorial and gamma related

Name Notation Discrete formula Continuous formula
Factorial
Gamma function
Double factorial


Binomial coefficient
Rising factorial
Falling factorial
Beta function
Harmonic number
Digamma function
Polygamma function
(of order m)

Notes:

Zeta function related

Hypergeometric functions

Note: many of the preceding functions are special cases of the following: