ArcSec
✖
ArcSec
Details

- Mathematical function, suitable for both symbolic and numerical manipulation.
- All results are given in radians.
- For real
outside the interval
to
, the results are always in the range
to
, excluding
.
- For certain special arguments, ArcSec automatically evaluates to exact values.
- ArcSec can be evaluated to arbitrary numerical precision.
- ArcSec automatically threads over lists.
- ArcSec[z] has a branch cut discontinuity in the complex
plane running from
to
.
- ArcSec can be used with Interval and CenteredInterval objects. »
Background & Context
- ArcSec is the inverse secant function. For a real number
, ArcSec[x] represents the radian angle measure,
,
, such that
.
- ArcSec automatically threads over lists. For certain special arguments, ArcSec automatically evaluates to exact values. When given exact numeric expressions as arguments, ArcSec may be evaluated to arbitrary numeric precision. Operations useful for manipulation of symbolic expressions involving ArcSec include FunctionExpand, TrigToExp, TrigExpand, Simplify, and FullSimplify.
- ArcSec is defined for complex argument
via
. ArcSec[z] has a branch cut discontinuity in the complex
plane.
- Related mathematical functions include Sec, ArcCsc, and ArcSech.
Examples
open allclose allBasic Examples (5)Summary of the most common use cases

https://wolfram.com/xid/0j44p8je-c8qfg

Divide by Degree to get results in degrees:

https://wolfram.com/xid/0j44p8je-h7l7rv

Plot over a subset of the reals:

https://wolfram.com/xid/0j44p8je-lkzh8

Plot over a subset of the complexes:

https://wolfram.com/xid/0j44p8je-kiedlx

Asymptotic expansion at Infinity:

https://wolfram.com/xid/0j44p8je-0dztkz

Asymptotic expansion at a singular point:

https://wolfram.com/xid/0j44p8je-k12ao4

Scope (41)Survey of the scope of standard use cases
Numerical Evaluation (6)

https://wolfram.com/xid/0j44p8je-da1yw


https://wolfram.com/xid/0j44p8je-fp1tk9

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

https://wolfram.com/xid/0j44p8je-ntnsyn

Evaluate for complex arguments:

https://wolfram.com/xid/0j44p8je-bt9pr

Evaluate ArcSec efficiently at high precision:

https://wolfram.com/xid/0j44p8je-di5gcr


https://wolfram.com/xid/0j44p8je-bq2c6r

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

https://wolfram.com/xid/0j44p8je-m0fih


https://wolfram.com/xid/0j44p8je-lmyeh7


https://wolfram.com/xid/0j44p8je-6flll

Or compute average-case statistical intervals using Around:

https://wolfram.com/xid/0j44p8je-cw18bq

Compute the elementwise values of an array:

https://wolfram.com/xid/0j44p8je-thgd2

Or compute the matrix ArcSec function using MatrixFunction:

https://wolfram.com/xid/0j44p8je-o5jpo

Specific Values (5)
Values of ArcSec at fixed points:

https://wolfram.com/xid/0j44p8je-nww7l

Simple exact values are generated automatically:

https://wolfram.com/xid/0j44p8je-xirge


https://wolfram.com/xid/0j44p8je-gp8fq9


https://wolfram.com/xid/0j44p8je-drqkdo

Zero of ArcSec:

https://wolfram.com/xid/0j44p8je-cw39qs

Find the value of satisfying equation
:

https://wolfram.com/xid/0j44p8je-f2hrld

https://wolfram.com/xid/0j44p8je-op0v0e


https://wolfram.com/xid/0j44p8je-yei1qb


https://wolfram.com/xid/0j44p8je-du4pxr

Visualization (3)
Plot the ArcSec function:

https://wolfram.com/xid/0j44p8je-ecj8m7


https://wolfram.com/xid/0j44p8je-bo5grg


https://wolfram.com/xid/0j44p8je-bac0f3


https://wolfram.com/xid/0j44p8je-epb4bn

Function Properties (10)
ArcSec is defined for all real values except from the interval :

https://wolfram.com/xid/0j44p8je-cl7ele


https://wolfram.com/xid/0j44p8je-de3irc

ArcSec lies between and
:

https://wolfram.com/xid/0j44p8je-evf2yr

Function range for arguments from the complex domain:

https://wolfram.com/xid/0j44p8je-fphbrc

ArcSec is not an analytic function:

https://wolfram.com/xid/0j44p8je-h5x4l2


https://wolfram.com/xid/0j44p8je-e434t9

ArcSec is monotonic in a specific range:

https://wolfram.com/xid/0j44p8je-g6kynf


https://wolfram.com/xid/0j44p8je-5pj03b


https://wolfram.com/xid/0j44p8je-fz9c6h


https://wolfram.com/xid/0j44p8je-m4ykug

ArcSec is injective:

https://wolfram.com/xid/0j44p8je-gi38d7


https://wolfram.com/xid/0j44p8je-ctca0g

ArcSec is not surjective:

https://wolfram.com/xid/0j44p8je-hkqec4


https://wolfram.com/xid/0j44p8je-hdm869

ArcSec is non-negative on its real domain:

https://wolfram.com/xid/0j44p8je-84dui

It has both singularity and discontinuity for x in [-1,1]:

https://wolfram.com/xid/0j44p8je-mdtl3h


https://wolfram.com/xid/0j44p8je-mn5jws

ArcSec is neither convex nor concave:

https://wolfram.com/xid/0j44p8je-kdss3

TraditionalForm formatting:

https://wolfram.com/xid/0j44p8je-hiukg

Differentiation (3)

https://wolfram.com/xid/0j44p8je-mmas49


https://wolfram.com/xid/0j44p8je-nfbe0l


https://wolfram.com/xid/0j44p8je-fxwmfc


https://wolfram.com/xid/0j44p8je-odmgl1

Integration (3)
Indefinite integral of ArcSec:

https://wolfram.com/xid/0j44p8je-bponid

Definite integral over the interval :

https://wolfram.com/xid/0j44p8je-b9jw7l


https://wolfram.com/xid/0j44p8je-d2d0wg


https://wolfram.com/xid/0j44p8je-jid800

Series Expansions (3)
Find the Taylor expansion using Series:

https://wolfram.com/xid/0j44p8je-ewr1h8

Plot the first three approximations for ArcSec around :

https://wolfram.com/xid/0j44p8je-binhar

Find series expansions at branch points and branch cuts:

https://wolfram.com/xid/0j44p8je-cn01tz


https://wolfram.com/xid/0j44p8je-cwcy3c

ArcSec can be applied to power series:

https://wolfram.com/xid/0j44p8je-bjwx3j

Function Identities and Simplifications (3)
Simplify expressions involving ArcSec:

https://wolfram.com/xid/0j44p8je-u9xlpa

Use TrigToExp to express in terms of logarithm:

https://wolfram.com/xid/0j44p8je-b85ut5

Use ExpToTrig to convert back:

https://wolfram.com/xid/0j44p8je-eohzma

Expand assuming real variables and
:

https://wolfram.com/xid/0j44p8je-se6

Function Representations (5)
Represent using ArcCos:

https://wolfram.com/xid/0j44p8je-ftreaf

Representation through inverse Jacobi functions:

https://wolfram.com/xid/0j44p8je-m9whnz


https://wolfram.com/xid/0j44p8je-i0p6v1

Represent using Hypergeometric2F1:

https://wolfram.com/xid/0j44p8je-ds7bqo

ArcSec can be represented in terms of MeijerG:

https://wolfram.com/xid/0j44p8je-n7uz12


https://wolfram.com/xid/0j44p8je-o11k

ArcSec can be represented as a DifferentialRoot:

https://wolfram.com/xid/0j44p8je-zbzsc

Applications (3)Sample problems that can be solved with this function
Branch cut of ArcSec runs along the real axis:

https://wolfram.com/xid/0j44p8je-ie1tol

Solve a differential equation:

https://wolfram.com/xid/0j44p8je-8c7

Visualize multiple complex trigonometric functions using Parallelize to speed up computations:

https://wolfram.com/xid/0j44p8je-z5brn

https://wolfram.com/xid/0j44p8je-i34ds

Properties & Relations (5)Properties of the function, and connections to other functions
Compose with inverse functions:

https://wolfram.com/xid/0j44p8je-guzqsd

Use PowerExpand to disregard multivaluedness of the ArcSec:

https://wolfram.com/xid/0j44p8je-3u

Alternatively, evaluate under additional assumptions:

https://wolfram.com/xid/0j44p8je-gywjjy

Use TrigToExp to express in terms of logarithm:

https://wolfram.com/xid/0j44p8je-l7iqf

Use ExpToTrig to convert back:

https://wolfram.com/xid/0j44p8je-e9b9y3

ArcSec gives the angle in radians, while ArcSecDegrees gives the same angle in degrees:

https://wolfram.com/xid/0j44p8je-0u4ktt


https://wolfram.com/xid/0j44p8je-8h1c0s

Use FunctionExpand to convert trigs of arctrigs into an algebraic function:

https://wolfram.com/xid/0j44p8je-blhuff


https://wolfram.com/xid/0j44p8je-4al45

Use Reduce to solve equations involving ArcSec:

https://wolfram.com/xid/0j44p8je-57rc7

Wolfram Research (1988), ArcSec, Wolfram Language function, https://reference.wolfram.com/language/ref/ArcSec.html (updated 2021).
Text
Wolfram Research (1988), ArcSec, Wolfram Language function, https://reference.wolfram.com/language/ref/ArcSec.html (updated 2021).
Wolfram Research (1988), ArcSec, Wolfram Language function, https://reference.wolfram.com/language/ref/ArcSec.html (updated 2021).
CMS
Wolfram Language. 1988. "ArcSec." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2021. https://reference.wolfram.com/language/ref/ArcSec.html.
Wolfram Language. 1988. "ArcSec." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2021. https://reference.wolfram.com/language/ref/ArcSec.html.
APA
Wolfram Language. (1988). ArcSec. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/ArcSec.html
Wolfram Language. (1988). ArcSec. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/ArcSec.html
BibTeX
@misc{reference.wolfram_2025_arcsec, author="Wolfram Research", title="{ArcSec}", year="2021", howpublished="\url{https://reference.wolfram.com/language/ref/ArcSec.html}", note=[Accessed: 02-May-2025
]}
BibLaTeX
@online{reference.wolfram_2025_arcsec, organization={Wolfram Research}, title={ArcSec}, year={2021}, url={https://reference.wolfram.com/language/ref/ArcSec.html}, note=[Accessed: 02-May-2025
]}