A formula I want to typeset contains a tripple line integral, i.e. a symbol that has three integral signs that are encircled. How can I do this?
I tried \oiiint, but that does not work. \iiint works on the contrary.
[Tex/LaTex] How to insert a triple line integral
math-mode
Related Solutions
If you redefine the largesymbols font, all large operators will be taken from the Euler font. Moreover, the call is wrong:
\DeclareSymbolFont{eulargesymbols}{U}{zeuex}{m}{n}
\DeclareMathSymbol{\intop}{\mathop}{eulargesymbols}{"52}
Here is the picture (on the right the usual symbol)
How does one discover what should be done? Well, it depends on the font one has to use. Let's make an example: we want some large symbols from the font used by mathpazo.
We find in mathpazo.sty what font is used:
\DeclareSymbolFont{largesymbols}{OMX}{zplm}{m}{n}
Thus we just change the symbolic name to something like pazolargesymbols and do as the previous case; since the encoding is OMX, which is the same normally used for math extension fonts, we know that the integral will be in the same slot as in the usual setting:
\DeclareMathSymbol{\intop}{\mathop}{pazolargesymbols}{"52}
One can find the standard definition in fontmath.ltx.
If the encoding is non standard, as in the case of eulervm, we need to check for the slot. However, eulervm.sty doesn't redefine \intop, so we can be confident that the usual slot is good. It could be different for other symbols.
Note that we have to define \intop rather than \int, because the latter is defined by LaTeX as
\def\int{\intop\nolimits}
The amsmath package does a different definition of \int, but it uses \intop for the symbol as well.
Option 1
\documentclass[preview,border=12pt,varwidth]{standalone}% change it back to your own document class
\usepackage{amsmath}
\begin{document}
\abovedisplayskip=0pt\relax% remove this line in your production
\[
\int \frac{1}{\cos^2\left(5 - \frac{3x}{4}\right)}\,\mathrm{d}x
\]
\end{document}
Option 2
\documentclass[preview,border=12pt,varwidth]{standalone}% change it back to your own document class
\usepackage{amsmath}
\begin{document}
\abovedisplayskip=0pt\relax% remove this line in your production
\[
\int \frac{1}{\cos^2\left(5 - \frac{3}{4}x\right)}\,\mathrm{d}x
\]
\end{document}
Option 3
Prof. Enrico likes this style I think.
\documentclass[preview,border=12pt,varwidth]{standalone}% change it back to your own document class
\usepackage{amsmath}
\begin{document}
\abovedisplayskip=0pt\relax% remove this line in your production
\[
\int \frac{1}{\cos^2(5 - 3x/4)}\,\mathrm{d}x
\]
\end{document}
Option 4
By Thorsten Donig's comment below.
\documentclass[preview,border=12pt,varwidth]{standalone}% change it back to your own document class
\usepackage{amsmath,xfrac}
\begin{document}
\abovedisplayskip=0pt\relax% remove this line in your production
\[
\int \frac{1}{\cos^2 (5 - \sfrac{3x}{4})}\,\mathrm{d}x
\]
\end{document}
Option ∞
Based on Qrrbrbirlbel's and Egreg's comments below.
\documentclass[preview,border=12pt]{standalone}% change it back to your own document class
\usepackage{amsmath,xfrac}
\begin{document}
\abovedisplayskip=0pt\relax% remove this line in your production
\begin{gather*}
\int \sec^2\left(5 - \tfrac{3x}{4}\right)\,\mathrm{d}x \\
\int \sec^2\left(5 - \tfrac 3 4 x\right)\,\mathrm{d}x \\
\int \sec^2(5 - 3x/4)\,\mathrm{d}x \\
\int \sec^2\left(5 - \sfrac{3x}{4}\right)\,\mathrm{d}x
\end{gather*}
\end{document}
Best Answer
The
mathdesignpackage defines\oiiint, as dotxfontsandpxfontspackages, according to the comprehensive symbols list.