导出 pgf/tikz 图形时出现问题

Question

当我尝试导出此图形时遇到错误。

\documentclass[12pt]{article}
\usepackage{pgf,tikz,pgfplots}
\pgfplotsset{compat=1.11}
\usepackage{mathrsfs}
\usetikzlibrary{arrows}
\pagestyle{empty}
\begin{document}
\begin{tikzpicture}[line cap=round,line join=round,>=triangle 45,x=1.0cm,y=1.0cm]
\clip(-3.,-3.) rectangle (3.,3.);
\draw[line width=0.8pt,smooth,samples=100,domain=-3.0:3.0] plot(\x,{(9.0-(\x)^(3.0))^(1/(3.0))});
\end{tikzpicture}
\end{document}