# How to write braces inside \sqrt[ in here ]{sth}? [duplicate]

This is what I want to write:

Apparently, the following doesn't work

\sqrt[ \sqrt[\log n]{n} ]{x}

The error is that the argument of \sqrt has an extra }. This seems like a bug to me. Is there a way to write this symbol?

## marked as duplicate by Schweinebacke, egreg, Community♦Mar 30 '17 at 17:51

• It should be \sqrt[{\sqrt[\log n]{n}}]{x}, but are you sure you want that monster? – egreg Mar 30 '17 at 17:35

Put the second \sqrt into {...}.

Edit: I've added a possible alternative to the monster.

\documentclass{article}
\usepackage{mathtools}
\begin{document}
$\sqrt[{\sqrt[\log n]{n}}]{x}$
I prefer this possibile alternative:
${x}^{{\bigl[{n}^{{(\log n)}^{-1}}\bigr]^{-1}}}$
\end{document}


• That's it. Should have thought about that! Thanks! – Nikos Mar 30 '17 at 17:37
• I know of this alternative, but i wanted to specifically emphasize the root sign. Your original answer is perfectly fine. This one is a welcome addition of course. – Nikos Mar 30 '17 at 20:28
• @RestlessC0bra There's a reason for creating the monster, then, hahaha! – CarLaTeX Mar 30 '17 at 20:30