\input{umtest-preamble} \usepackage{unicode-math} \usepackage{amsmath} \usepackage{graphicx} \setmathfont{Cambria Math} \newcommand*{\test}[1]{% \parbox[b][50pt]{50pt}{\scalebox{3}{$#1$}}% } \begin{document} \test{\sqrt[a]{b}} \test{\sqrt[\uproot{10}a]{b}} \test{\sqrt[\leftroot{10}a]{b}} \test{\sqrt[\leftroot{10}\uproot{10}a]{b}} \end{document}