[Tex/LaTex] Big double integral sign

math-mode

I'm trying to make a double integral, but, somewhy, the sign appears small compared to regular integral signs, does anybody knows why? And how do I solve this? I am using the 'equation' environment

Best Answer

Package `amsmath`

\documentclass{article}
\usepackage{amsmath}

\begin{document}
\[
  \int \iint
\]
\end{document}

$Result \iint of package amsmath$

The size is the same, maybe, you want to use this.

Package `wasysym`

\documentclass{article}
\usepackage{wasysym}

\begin{document}
\[
  \int \iint
\]
\end{document}

$Result \iint of package wasysym$

Package wasysym does not provide the larger more slanted form. However, the standard integral can be redefined to match the double integral:

\documentclass{article}
\usepackage[integrals]{wasysym}

\begin{document}
\[
  \int \iint
\]
\end{document}

Other

There are lots of other packages, which provide the double integral, but most of them also change the appearance of other symbols (mathabx, txfonts, ...). See The Comprehensive LaTeX Symbol List.

Related Solutions

[Tex/LaTex] How to insert a triple line integral

The mathdesign package defines \oiiint, as do txfonts and pxfonts packages, according to the comprehensive symbols list.

[Tex/LaTex] making a big summation sign

You can use the command \mathlarger of the relsize package. It increases the size and it can be nested. For example:

\documentclass{article}
\usepackage{amsmath}
\usepackage{relsize}
\begin{document}
\begin{equation}‎
‎‎\cos x‎ ‎=‎ \mathlarger{\mathlarger{‎‎\sum}}_{n=0}^{\infty}\frac{(ix)^2n}{(2n)!}‎‎
\end{equation}‎
\end{document}

equation with bigger sum symbol

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