# Typesetting an empty square root

Is there a preferred way to typeset an empty sqrt? What I'm doing now is \sqrt{\phantom{a}}, are there other/preferred ways like a standalone symbol? Or should I just create a new macro with the phantom a?

• I'd just use \surd unless you specifically need the top bar. – Nicola Talbot Dec 15 '13 at 13:27
• I didn't know about \surd When the sqrt is introduced in mathematical textbooks, how is the empty symbol printed? Is it ok to print it without the top bar? – Andreas Hettel Dec 15 '13 at 13:30
• Where the Chicago Manual of Style writes "The radical sign √ is used to denote the square root" I would type that in LaTeX as The radical sign $\surd$ is used to denote the square root. – Nicola Talbot Dec 15 '13 at 13:47
• @NicolaTalbot Ok, thanks, I'll check if it is also used in the local textbooks and if yes I'll follow your advice. – Andreas Hettel Dec 15 '13 at 13:50

The \surd command just produces the radical symbol √ as opposed to \sqrt{stuff} which typesets the square root of stuff with a bar over stuff. The Chicago Manual of Style uses just the radical symbol in the text "The radical sign √ is used to denote the square root".

\documentclass{article}

\begin{document}
Compare:

\begin{itemize}
\item The radical sign $\surd$ is used to denote the square root.

\item The radical sign $\sqrt{}$ is used to denote the square root.

\item The radical sign $\sqrt{\phantom{x}}$ is used to denote the square root.
\end{itemize}

Alternatively: the square root of $x$ is denoted $\surd x$ or $\sqrt{x}$.

\end{document}


The Penguin Dictionary of Mathematics also just uses the radical sign (without an over bar) when defining both the terms "radical" and "square root".

• Notice that \surd places the symbol a bit higher, hence producing more pleasant vertically centered output. – yo' Dec 15 '13 at 17:51