# Large cube root and fourth root in unicode-math

XITS math font, for example, has the large \cuberoot etc (uni221B.size1 etc). But different from \sqrt, the large variants will not be used automatically. So how can I use the large \cuberoot and \fourthroot in unicode-math?

## Update

Now \cuberoot and \fourthroot will load the large symbols automatically in unicode-math v0.8m (2018/07/29).

• 2221B I assume you mean – David Carlisle Jun 27 '18 at 6:49
• It's actually U+221B and U+221C. – stone-zeng Jun 27 '18 at 6:58

## 1 Answer

unicode-math is supposed to have an interface for declaring radicals but it didn't work as I expect.

However the xetex/luatex primitive works:

\documentclass{article}

\usepackage{unicode-math}

\setmathfont{XITS Math}

\begin{document}

$\sqrt{x} \quad \sqrt{\frac{\frac{A}{B}}{C}}$

$\cuberoot{x} \quad \cuberoot{\frac{\frac{A}{B}}{C}}$

\def\cbr{\Uradical\symoperators "0221B\relax}
$\cbr{x} \quad \cbr{\frac{\frac{A}{B}}{C}}$
\end{document}