Centering and spacing two subscript lines under a double integral
You can define a general purpose macro \widerof
, with three arguments:
- (optional, default
c
) the alignment in the box; - the symbol to print;
- the symbol to compare the width with.
In the example I changed 0
to -1
just to show all types of alignment. I also used \smashoperator
from mathtools
.
\documentclass{amsbook}
\usepackage{mathtools}
\usepackage[frenchstyle]{kpfonts}
\makeatletter
\newcommand{\widerof}[3][c]{\mathpalette\widerof@{{#1}{#2}{#3}}}
\newcommand{\widerof@}[2]{\widerof@@{#1}#2}
\newcommand{\widerof@@}[4]{%
% #1=math style, #2=alignment, #3=symbol to print, #4=symbol to compare to
\begingroup
\sbox\z@{$\m@th#1#3$}%
\sbox\tw@{$\m@th#1#4$}%
\makebox[\ifdim\wd\z@>\wd\tw@ \wd\z@\else \wd\tw@\fi][#2]{$\m@th#1#3$}%
\endgroup
}
\makeatother
\begin{document}
\[
V_n=
V_{n-2}
\smashoperator{\iint\limits_{
\substack{
\widerof[r]{0}{-1} < \widerof{\theta}{r} < \widerof[l]{2\pi}{1} \\
\widerof[r]{-1}{0} < \widerof{r}{\theta} < \widerof[l]{1}{2\pi}
}
}} (1 - r^2)^{\frac{n-2}{2}} r\D{\theta}\D{r}
\]
\end{document}
Here, I use a TABstack. If you want the lines with less vertical gap, that can easily be done, as an optional argument to \tabularstackunder
(default 3pt gap).
\documentclass{amsbook}
\usepackage{tabstackengine}
\usepackage[frenchstyle]{kpfonts}
\usepackage{mathtools}
\TABstackMath
\setstacktabulargap{0pt}
\begin{document}
\[
\TABstackMathstyle{\scriptstyle}
V_n
= V_{n-2} \iint\limits_{\mathclap{\tabularstackunder{rcl}{
0<&\theta&<2\pi}{
0<&r&<1}}}
(1 - r^2)^{\frac{n-2}{2}} r\D{\theta}\D{r}
\]
\end{document}
Use alignedat
environment.
\documentclass{amsbook}
\usepackage[frenchstyle]{kpfonts}
\usepackage{mathtools}
\begin{document}
\[
V_n = V_{n-2} \iint\limits_{\scriptsize\mathclap{
\begin{alignedat}{2}
0 &< \theta & &< 2\pi \\[-.6em]
0 &< \:r & &< 1
\end{alignedat}
}}
(1 - r^2)^{\frac{n-2}{2}} r\D{\theta}\D{r}
\]
\end{document}