# HypergeometricU

HypergeometricU[a,b,z]

is the Tricomi confluent hypergeometric function .

# Examples

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## Basic Examples(5)

Evaluate numerically:

Plot over a subset of the reals:

Plot over a subset of the complexes:

Series expansion at the origin:

Series expansion at Infinity:

## Scope(39)

### Numerical Evaluation(5)

Evaluate to high precision:

The precision of the output tracks the precision of the input:

Evaluate for complex arguments:

Evaluate HypergeometricU efficiently at high precision:

HypergeometricU threads elementwise over lists:

HypergeometricU can be used with Interval and CenteredInterval objects:

### Specific Values(3)

HypergeometricU automatically evaluates to simpler functions for certain parameters:

Limiting value at infinity:

Find a value of satisfying the equation :

### Visualization(3)

Plot the HypergeometricU function:

Plot HypergeometricU as a function of its second parameter:

Plot the real part of :

Plot the imaginary part of :

### Function Properties(9)

Real domain of HypergeometricU:

Complex domain of HypergeometricU:

is not an analytic function:

is neither non-decreasing nor non-increasing on its real domain:

is injective:

is not surjective:

is positive on its real domain:

has both singularity and discontinuity for z0:

is convex on its real domain:

### Differentiation(3)

First derivative:

Higher derivatives:

Plot higher derivatives for and :

Formula for the derivative:

### Integration(3)

Indefinite integral HypergeometricU:

Definite integral of HypergeometricU:

More integrals:

### Series Expansions(3)

Series expansion for HypergeometricU:

Plot the first three approximations for around :

Expand HypergeometricU in series around infinity:

Apply HypergeometricU to a power series:

### Integral Transforms(3)

Compute the Laplace transform using LaplaceTransform:

### Function Identities and Simplifications(2)

Argument simplification:

Recurrence identities:

### Function Representations(5)

Primary definition:

Representation through Gamma and Hypergeometric1F1:

HypergeometricU can be represented in terms of MeijerG:

HypergeometricU can be represented as a DifferentialRoot:

## Applications(3)

Solve the confluent hypergeometric differential equation:

Borel summation of the divergent series for the function gives HypergeometricU:

Define distribution for scaled condition number of a WishartMatrixDistribution:

Sample the scaled condition number of a large matrix and check that it agrees with asymptotic closed-form distribution:

The asymptotic scaled condition number distribution has infinite mean:

## Properties & Relations(3)

Use FunctionExpand to expand HypergeometricU into simpler functions:

Integrate may give results involving HypergeometricU:

HypergeometricU can be represented as a DifferenceRoot:

## Possible Issues(1)

The default setting of \$MaxExtraPrecision can be insufficient to obtain requested precision:

A larger setting for \$MaxExtraPrecision may be needed:

## Neat Examples(2)

Visualize the confluency relation :

Plot the Riemann surface of :

Wolfram Research (1988), HypergeometricU, Wolfram Language function, https://reference.wolfram.com/language/ref/HypergeometricU.html (updated 2022).

#### Text

Wolfram Research (1988), HypergeometricU, Wolfram Language function, https://reference.wolfram.com/language/ref/HypergeometricU.html (updated 2022).

#### CMS

Wolfram Language. 1988. "HypergeometricU." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2022. https://reference.wolfram.com/language/ref/HypergeometricU.html.

#### APA

Wolfram Language. (1988). HypergeometricU. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/HypergeometricU.html

#### BibTeX

@misc{reference.wolfram_2024_hypergeometricu, author="Wolfram Research", title="{HypergeometricU}", year="2022", howpublished="\url{https://reference.wolfram.com/language/ref/HypergeometricU.html}", note=[Accessed: 17-June-2024 ]}

#### BibLaTeX

@online{reference.wolfram_2024_hypergeometricu, organization={Wolfram Research}, title={HypergeometricU}, year={2022}, url={https://reference.wolfram.com/language/ref/HypergeometricU.html}, note=[Accessed: 17-June-2024 ]}