WOLFRAM

BesselY[n,z]

gives the Bessel function of the second kind TemplateBox[{n, z}, BesselY].

Details

  • Mathematical function, suitable for both symbolic and numerical manipulation.
  • TemplateBox[{n, z}, BesselY] satisfies the differential equation .
  • BesselY[n,z] has a branch cut discontinuity in the complex z plane running from to .
  • FullSimplify and FunctionExpand include transformation rules for BesselY.
  • For certain special arguments, BesselY automatically evaluates to exact values.
  • BesselY can be evaluated to arbitrary numerical precision.
  • BesselY automatically threads over lists.
  • BesselY can be used with Interval and CenteredInterval objects. »

Examples

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Basic Examples  (5)Summary of the most common use cases

Evaluate numerically:

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Plot over a subset of the reals:

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Plot over a subset of the complexes:

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Series expansion at the origin:

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Series expansion at Infinity:

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Scope  (44)Survey of the scope of standard use cases

Numerical Evaluation  (6)

Evaluate numerically:

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Evaluate to high precision:

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

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Evaluate for complex arguments and parameters:

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Evaluate BesselY efficiently at high precision:

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Compute worst-case guaranteed intervals using Interval and CenteredInterval objects:

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Or compute average-case statistical intervals using Around:

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Compute the elementwise values of an array:

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Or compute the matrix BesselY function using MatrixFunction:

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Specific Values  (4)

Value of BesselY for integers () orders at :

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For half-integer indices, BesselY evaluates to elementary functions:

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Limiting value at infinity:

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The first three zeros of TemplateBox[{0, x}, BesselY]:

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Find the first zero of TemplateBox[{0, x}, BesselY] using Solve:

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Visualize the result:

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Visualization  (3)

Plot the BesselY function for integer orders ():

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Plot the real and imaginary parts of the BesselY function for integer orders ():

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Plot the real part of TemplateBox[{0, z}, BesselY]:

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Plot the imaginary part of TemplateBox[{0, z}, BesselY]:

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Function Properties  (10)

TemplateBox[{n, z}, BesselY] is defined for all real values greater than 0:

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Complex domain:

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Approximate function range of TemplateBox[{0, z}, BesselY]:

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Approximate function range of TemplateBox[{1, z}, BesselY]:

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TemplateBox[{n, z}, BesselY] is not an analytic function:

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BesselY is neither non-decreasing nor non-increasing:

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BesselY is not injective:

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BesselY is not surjective:

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BesselY is neither non-negative nor non-positive:

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TemplateBox[{n, z}, BesselY] has both singularity and discontinuity for z0:

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BesselY is neither convex nor concave:

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TraditionalForm formatting:

Differentiation  (3)

First derivative:

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Higher derivatives:

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Plot higher derivatives for :

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Formula for the ^(th) derivative:

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Integration  (3)

Indefinite integral of BesselY:

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Integrate expressions involving BesselY:

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Definite integral of BesselY over its real domain:

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Series Expansions  (5)

Taylor expansion for TemplateBox[{0, x}, BesselY] around :

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Plot the first three approximations for TemplateBox[{0, x}, BesselY] around :

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General term in the series expansion of BesselY:

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Asymptotic approximation of BesselY:

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Taylor expansion at a generic point:

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BesselY can be applied to a power series:

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Integral Transforms  (3)

Compute the Laplace transform using LaplaceTransform:

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HankelTransform:

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MellinTransform:

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Function Identities and Simplifications  (3)

Use FullSimplify to simplify Bessel functions:

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Recurrence relation z (TemplateBox[{{n, -, 1}, z}, BesselY]+TemplateBox[{{n, +, 1}, z}, BesselY])=2 n TemplateBox[{n, z}, BesselY]:

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For integer and arbitrary fixed , TemplateBox[{{-, n}, z}, BesselY]=(-1)^n TemplateBox[{n, z}, BesselY]:

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Function Representations  (4)

Integral representation of BesselY:

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Represent using BesselJ and Sin for non-integer :

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BesselY can be represented in terms of MeijerG:

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BesselY can be represented as a DifferenceRoot:

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Applications  (2)Sample problems that can be solved with this function

Solve the Bessel differential equation:

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Solve a differential equation:

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Solve the inhomogeneous Bessel differential equation:

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Properties & Relations  (3)Properties of the function, and connections to other functions

Use FullSimplify to simplify Bessel functions:

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BesselY can be represented as a DifferentialRoot:

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The exponential generating function for BesselY:

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Possible Issues  (1)Common pitfalls and unexpected behavior

With numeric arguments, half-integer Bessel functions are not automatically evaluated:

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For symbolic arguments they are:

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This can lead to major inaccuracies in machine-precision evaluation:

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Neat Examples  (1)Surprising or curious use cases

Plot the Riemann surface of TemplateBox[{0, z}, BesselY]:

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Plot the Riemann surface of TemplateBox[{{1, /, 3}, z}, BesselY]:

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

Text

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

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

CMS

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

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

APA

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

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

BibTeX

@misc{reference.wolfram_2025_bessely, author="Wolfram Research", title="{BesselY}", year="2022", howpublished="\url{https://reference.wolfram.com/language/ref/BesselY.html}", note=[Accessed: 01-June-2025 ]}

@misc{reference.wolfram_2025_bessely, author="Wolfram Research", title="{BesselY}", year="2022", howpublished="\url{https://reference.wolfram.com/language/ref/BesselY.html}", note=[Accessed: 01-June-2025 ]}

BibLaTeX

@online{reference.wolfram_2025_bessely, organization={Wolfram Research}, title={BesselY}, year={2022}, url={https://reference.wolfram.com/language/ref/BesselY.html}, note=[Accessed: 01-June-2025 ]}

@online{reference.wolfram_2025_bessely, organization={Wolfram Research}, title={BesselY}, year={2022}, url={https://reference.wolfram.com/language/ref/BesselY.html}, note=[Accessed: 01-June-2025 ]}