SurdForm
✖
SurdForm
is an option to RadicalBox and SqrtBox that indicates whether the radical represents a Surd expression.
Details

- With the default value SurdFormFalse, SqrtBox and RadicalBox represent principal roots. In particular, SqrtBox[x] is interpreted as Sqrt[x], and RadicalBox[x,n] is interpreted as x^(1/n).
- With the specification SurdFormTrue, SqrtBox and RadicalBox represent real roots computed using Surd. In particular, SqrtBox[x] is interpreted as Surd[x,2], and RadicalBox[x,n] is interpreted as Surd[x,n].
- SurdFormTrue displays with a short vertical line on the right side of the radical sign.
- A templated RadicalBox with SurdFormTrue can be entered as
surd
, and
moves between the fields.
Examples
open allclose allBasic Examples (4)Summary of the most common use cases
Compare the display of SqrtBox with and without SurdFormTrue:

https://wolfram.com/xid/0i1iv21cq-x78hs7

The interpretation of SqrtBox depends on the value of SurdForm:

https://wolfram.com/xid/0i1iv21cq-80ldiy

The first expression is interpreted as a fractional power, the second as a Surd expression:

https://wolfram.com/xid/0i1iv21cq-m5et2j

Compare the display of RadicalBox with and without SurdFormTrue:

https://wolfram.com/xid/0i1iv21cq-jdjozx

The interpretation of RadicalBox depends on the value of SurdForm:

https://wolfram.com/xid/0i1iv21cq-wp0c40

The first expression is interpreted as a fractional power, the second as a Surd expression:

https://wolfram.com/xid/0i1iv21cq-2p3qyq

Possible Issues (1)Common pitfalls and unexpected behavior
SurdForm can be set as a StyleBox or higher-level option setting:

https://wolfram.com/xid/0i1iv21cq-vzfnkw
The notebook front end respects any such inherited setting for rendering purposes:

https://wolfram.com/xid/0i1iv21cq-o457oh

However, the inherited setting is not used to interpret the expression:

https://wolfram.com/xid/0i1iv21cq-y8zfov

Wolfram Research (2012), SurdForm, Wolfram Language function, https://reference.wolfram.com/language/ref/SurdForm.html.
Text
Wolfram Research (2012), SurdForm, Wolfram Language function, https://reference.wolfram.com/language/ref/SurdForm.html.
Wolfram Research (2012), SurdForm, Wolfram Language function, https://reference.wolfram.com/language/ref/SurdForm.html.
CMS
Wolfram Language. 2012. "SurdForm." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/SurdForm.html.
Wolfram Language. 2012. "SurdForm." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/SurdForm.html.
APA
Wolfram Language. (2012). SurdForm. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/SurdForm.html
Wolfram Language. (2012). SurdForm. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/SurdForm.html
BibTeX
@misc{reference.wolfram_2025_surdform, author="Wolfram Research", title="{SurdForm}", year="2012", howpublished="\url{https://reference.wolfram.com/language/ref/SurdForm.html}", note=[Accessed: 08-July-2025
]}
BibLaTeX
@online{reference.wolfram_2025_surdform, organization={Wolfram Research}, title={SurdForm}, year={2012}, url={https://reference.wolfram.com/language/ref/SurdForm.html}, note=[Accessed: 08-July-2025
]}