[Tex/LaTex] One overall subscript with double integral

Question

I want to assign only one overall subscript that cover the both integral symbols in double integration, I tried:

\begin{equation}
T_y=\iint_A \tau_{xy}\,dA=0
\end{equation} 

but it only goes with second integral?

Answer 1

You can use \limits to accomplish the job. The package mathtools provides good enhancements to the basic features of LaTeX typesetting.

\documentclass{article}
\usepackage{mathtools}
\begin{document}
\begin{gather}
\iiint\limits_V \mu(t,u,v,w) \,dt\,du\,dv\,dw \\
T_y=\iint\limits_A \tau_{xy}\,dA=0
\end{gather} 
\end{document}