Sqrt
✖
Sqrt
Details

- Mathematical function, suitable for both symbolic and numerical manipulation.
can be entered using
or ∖(∖@z∖).
- Sqrt[z] is converted to
.
- Sqrt[z^2] is not automatically converted to z.
- Sqrt[a b] is not automatically converted to Sqrt[a]Sqrt[b].
- These conversions can be done using PowerExpand, but will typically be correct only for positive real arguments.
- For certain special arguments, Sqrt automatically evaluates to exact values.
- Sqrt can be evaluated to arbitrary numerical precision.
- Sqrt automatically threads over lists. »
- In StandardForm, Sqrt[z] is printed as
.
- √z can also be used for input. The √ character is entered as
sqrt
or \[Sqrt].
Examples
open allclose allBasic Examples (6)Summary of the most common use cases

https://wolfram.com/xid/0bud5a-vfm


https://wolfram.com/xid/0bud5a-bgm

Negative numbers have imaginary square roots:

https://wolfram.com/xid/0bud5a-ko7

Plot over a subset of the reals:

https://wolfram.com/xid/0bud5a-qyx

Plot over a subset of the complexes:

https://wolfram.com/xid/0bud5a-kiedlx


https://wolfram.com/xid/0bud5a-x21

It can be simplified to if one assumes
:

https://wolfram.com/xid/0bud5a-gah

Scope (39)Survey of the scope of standard use cases
Numerical Evaluation (7)

https://wolfram.com/xid/0bud5a-l274ju


https://wolfram.com/xid/0bud5a-b0wt9

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

https://wolfram.com/xid/0bud5a-y7k4a


https://wolfram.com/xid/0bud5a-hfml09

Evaluate efficiently at high precision:

https://wolfram.com/xid/0bud5a-di5gcr


https://wolfram.com/xid/0bud5a-bq2c6r

Sqrt can deal with real‐valued intervals:

https://wolfram.com/xid/0bud5a-bosfyx

Compute the elementwise values of an array using automatic threading:

https://wolfram.com/xid/0bud5a-thgd2

Or compute the matrix Sqrt function using MatrixFunction:

https://wolfram.com/xid/0bud5a-o5jpo

Compute average-case statistical intervals using Around:

https://wolfram.com/xid/0bud5a-cw18bq

Specific Values (4)
Values of Sqrt at fixed points:

https://wolfram.com/xid/0bud5a-nww7l


https://wolfram.com/xid/0bud5a-bmqd0y


https://wolfram.com/xid/0bud5a-uf5tg8


https://wolfram.com/xid/0bud5a-fvj8gv

Find a value of for which
using Solve:

https://wolfram.com/xid/0bud5a-f2hrld


https://wolfram.com/xid/0bud5a-vl0g15


https://wolfram.com/xid/0bud5a-bv3wsh

Visualization (4)
Plot the real and imaginary parts of the Sqrt function:

https://wolfram.com/xid/0bud5a-ecj8m7

Compare the real and imaginary parts of and
(Surd[x,2]):

https://wolfram.com/xid/0bud5a-5lbi4g


https://wolfram.com/xid/0bud5a-dbvuei


https://wolfram.com/xid/0bud5a-66a6z


https://wolfram.com/xid/0bud5a-epb4bn

Function Properties (10)
The real domain of Sqrt:

https://wolfram.com/xid/0bud5a-cl7ele

It is defined for all complex values:

https://wolfram.com/xid/0bud5a-de3irc

Sqrt achieves all non-negative values on the reals:

https://wolfram.com/xid/0bud5a-evf2yr

The range for complex values is the right half-plane, excluding the negative imaginary axis:

https://wolfram.com/xid/0bud5a-bwti4o


https://wolfram.com/xid/0bud5a-sub


https://wolfram.com/xid/0bud5a-cac

Enter a √ character as sqrt
or \[Sqrt], followed by a number:

https://wolfram.com/xid/0bud5a-44bmec


https://wolfram.com/xid/0bud5a-h5x4l2


https://wolfram.com/xid/0bud5a-e434t9

is neither non-decreasing nor non-increasing:

https://wolfram.com/xid/0bud5a-g6kynf

However, it is increasing where it is real valued:

https://wolfram.com/xid/0bud5a-efeacu


https://wolfram.com/xid/0bud5a-gi38d7


https://wolfram.com/xid/0bud5a-ctca0g


https://wolfram.com/xid/0bud5a-hkqec4


https://wolfram.com/xid/0bud5a-hdm869

is non-negative on its domain of definition:

https://wolfram.com/xid/0bud5a-xt0yav

has a branch cut singularity for
:

https://wolfram.com/xid/0bud5a-mdtl3h

However, it is continuous at the origin:

https://wolfram.com/xid/0bud5a-h82s2c

is neither convex nor concave:

https://wolfram.com/xid/0bud5a-kdss3

However, it is concave where it is real valued:

https://wolfram.com/xid/0bud5a-m0swuh

Differentiation (3)
The first derivative with respect to z:

https://wolfram.com/xid/0bud5a-krpoah

Higher derivatives with respect to z:

https://wolfram.com/xid/0bud5a-z33jv

Plot the higher derivatives with respect to z:

https://wolfram.com/xid/0bud5a-fxwmfc

Formula for the derivative with respect to z:

https://wolfram.com/xid/0bud5a-cb5zgj

Integration (3)
Compute the indefinite integral using Integrate:

https://wolfram.com/xid/0bud5a-bponid


https://wolfram.com/xid/0bud5a-op9yly


https://wolfram.com/xid/0bud5a-b9jw7l


https://wolfram.com/xid/0bud5a-cas


https://wolfram.com/xid/0bud5a-76sc

Series Expansions (4)
Find the Taylor expansion using Series:

https://wolfram.com/xid/0bud5a-ewr1h8

Plots of the first three approximations around :

https://wolfram.com/xid/0bud5a-binhar

The general term in the series expansion using SeriesCoefficient:

https://wolfram.com/xid/0bud5a-dznx2j

The first-order Fourier series:

https://wolfram.com/xid/0bud5a-f64drv

The Taylor expansion at a generic point:

https://wolfram.com/xid/0bud5a-jwxla7

Function Identities and Simplifications (4)

https://wolfram.com/xid/0bud5a-d3qxpd


https://wolfram.com/xid/0bud5a-57omz

is not automatically replaced by
:

https://wolfram.com/xid/0bud5a-pvrtvt

It can be simplified to if one assumes
:

https://wolfram.com/xid/0bud5a-bg5s5j

It can be simplified to if one assumes
:

https://wolfram.com/xid/0bud5a-7y6cs0

PowerExpand can be used to force cancellation without assumptions:

https://wolfram.com/xid/0bud5a-v6bnb

Expand assuming real variables x and y:

https://wolfram.com/xid/0bud5a-wunchk

Applications (4)Sample problems that can be solved with this function
Roots of a quadratic polynomial:

https://wolfram.com/xid/0bud5a-pchs78

Generate periodic continued fractions:

https://wolfram.com/xid/0bud5a-s9c


https://wolfram.com/xid/0bud5a-frk


https://wolfram.com/xid/0bud5a-l92h54

Solve a differential equation with Sqrt:

https://wolfram.com/xid/0bud5a-nfw6r

Compute an elliptic integral from the Sqrt function:

https://wolfram.com/xid/0bud5a-h2kodf

Properties & Relations (12)Properties of the function, and connections to other functions
Sqrt[x] and Surd[x,2] are the same for non-negative real values:

https://wolfram.com/xid/0bud5a-4ldjlp

For negative reals, Sqrt gives an imaginary result, whereas the real-valued Surd reports an error:

https://wolfram.com/xid/0bud5a-rhfa5d


Reduce combinations of square roots:

https://wolfram.com/xid/0bud5a-kz9

Evaluate power series involving square roots:

https://wolfram.com/xid/0bud5a-yvu

Expand a complex square root assuming variables are real valued:

https://wolfram.com/xid/0bud5a-c2e

Factor polynomials with square roots in coefficients:

https://wolfram.com/xid/0bud5a-qrf


https://wolfram.com/xid/0bud5a-l84

Simplify handles expressions involving square roots:

https://wolfram.com/xid/0bud5a-oav

There are many subtle issues in handling square roots for arbitrary complex arguments:

https://wolfram.com/xid/0bud5a-h7a

PowerExpand expands forms involving square roots:

https://wolfram.com/xid/0bud5a-wy1

It generically assumes that all variables are positive:

https://wolfram.com/xid/0bud5a-ghq

Finite sums of integers and square roots of integers are algebraic numbers:

https://wolfram.com/xid/0bud5a-phz

Take limits accounting for branch cuts:

https://wolfram.com/xid/0bud5a-xio


https://wolfram.com/xid/0bud5a-nz7

Sqrt can be represented as a DifferentialRoot:

https://wolfram.com/xid/0bud5a-ve17u

The generating function for Sqrt:

https://wolfram.com/xid/0bud5a-pz93yz


https://wolfram.com/xid/0bud5a-dab3fj

Possible Issues (3)Common pitfalls and unexpected behavior
Square root is discontinuous across its branch cut along the negative real axis:

https://wolfram.com/xid/0bud5a-jrx


https://wolfram.com/xid/0bud5a-ohr

Sqrt[x^2] cannot automatically be reduced to x:

https://wolfram.com/xid/0bud5a-t3a


https://wolfram.com/xid/0bud5a-lyn

With x assumed positive, the simplification can be done:

https://wolfram.com/xid/0bud5a-xoh

Use PowerExpand to do the formal reduction:

https://wolfram.com/xid/0bud5a-m8f

Along the branch cut, these are not the same:

https://wolfram.com/xid/0bud5a-mz6

Neat Examples (2)Surprising or curious use cases
Approximation to GoldenRatio:

https://wolfram.com/xid/0bud5a-eho


https://wolfram.com/xid/0bud5a-y10

Riemann surface for square root:

https://wolfram.com/xid/0bud5a-uec

Wolfram Research (1988), Sqrt, Wolfram Language function, https://reference.wolfram.com/language/ref/Sqrt.html (updated 1996).
Text
Wolfram Research (1988), Sqrt, Wolfram Language function, https://reference.wolfram.com/language/ref/Sqrt.html (updated 1996).
Wolfram Research (1988), Sqrt, Wolfram Language function, https://reference.wolfram.com/language/ref/Sqrt.html (updated 1996).
CMS
Wolfram Language. 1988. "Sqrt." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 1996. https://reference.wolfram.com/language/ref/Sqrt.html.
Wolfram Language. 1988. "Sqrt." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 1996. https://reference.wolfram.com/language/ref/Sqrt.html.
APA
Wolfram Language. (1988). Sqrt. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Sqrt.html
Wolfram Language. (1988). Sqrt. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Sqrt.html
BibTeX
@misc{reference.wolfram_2025_sqrt, author="Wolfram Research", title="{Sqrt}", year="1996", howpublished="\url{https://reference.wolfram.com/language/ref/Sqrt.html}", note=[Accessed: 28-March-2025
]}
BibLaTeX
@online{reference.wolfram_2025_sqrt, organization={Wolfram Research}, title={Sqrt}, year={1996}, url={https://reference.wolfram.com/language/ref/Sqrt.html}, note=[Accessed: 28-March-2025
]}