Adding white space under a letter or symbol [duplicate]

Question

Possible Duplicate:
Nice-looking p-th roots

There is symbol overlap in $\sqrt[a_1]{x}$. Is there a way to increase the vertical position of $a_1$?

\documentclass{article}
\begin{document}
$\sqrt[a_{1}]{x}$.
\end{document}

Answer 1

if you're using the amsmath package, you can use \uproot:

$\sqrt[\uproot{2} {a_{1}}]{x}$.

some experimentation may be required to determine the best spacing.

there's also \leftroot to shift the index horizontally.

both \uproot and \leftroot will accept a negative value to shift the index in the opposite direction.

by the way, this has been addressed before, in using-leftroot-uproot-with-closed-square-root-symbol and nice-looking-p-th-roots.

Answer 2

Here's an option, in the form of a new command \Sqrt[<index>][<raise>]{<root>}:

\documentclass{article}
\usepackage{xparse}% http://ctan.org/pkg/xparse
\NewDocumentCommand{\Sqrt}{O{} O{0pt} m}{%
  \sqrt[\raisebox{#2}{$\scriptscriptstyle#1$}]{#3}%
}
\begin{document}
$\sqrt[a_{1}]{x}$. $\Sqrt[a_{1}]{x}$. 
$\Sqrt[a_{1}][1pt]{x}$. $\Sqrt[a_{1}][2pt]{x}$.
\end{document}

It may be futile though to introduce a new command for a very small case. On a side note, using subscripts in \scriptscriptstyle (the font size used to indicate the root index), doesn't translate very well (note the similarly-sized 1 compared to a).