# Show integration limits above & below the integral

Well considering this code, the "E" is shown after the integral:

$$m = \iiint_E \rho \ \mathrm{d}V$$


The limit is shown slightly behind the number, how can I place it in the middle below the triple integral?

You need to insert \limits after \iiiint:

\documentclass{article}
\usepackage{amsmath} % for \iiint macro
\begin{document}
$$m = \iiint\limits_E \rho \, \mathrm{d}V$$
\end{document}

• May I ask why you put the comma between the rho and the integrant? - I added the extra backslash to add a space. – paul23 Oct 18 '14 at 16:17
• @paul23 - Actually, I didn't put in a comma, ,; instead, I put in the \, macro, which inserts a typographic thinspace. In contrast, the \  macro in your example inserts a full interword space, which is probably more whitespace than is typographically optimal. – Mico Oct 18 '14 at 17:14
• I have an old, how-to-typeset-math, book from the 60s. It's British (Oxford), and recommends a thickspace in that place. (It also recommends placing the limits above and below the integral sign, even for single integral signs.) In American sources, I can only recall ever seeing thinspace recommended. – dedded Oct 18 '14 at 22:16
• @dedded - In TeX's math mode, a typographic thickspace may be generated via either \; or \thickspace. The default values of thin-, med-, and thickspace, in both plain TeX and the LaTeX kernel, are 3mu, 4mu, and 5mu, respectively. (Recall that 1em=18mu. "Why 18mu to the em?", you may ask. I have no idea...) The difference between thin- and thickspace thus isn't that huge -- though certainly noticeable to the human eye. – Mico Oct 19 '14 at 9:41
• I thought an inter-word space was 0.25em (unstretched, of course), or 4.5mu, or about a thickspace. I was just noting that there was at least one style guide that regarded this as "optimal". (The book is The Printing of Mathematics by T.W.Chaundy; rule 30b.) Like you, I use a thinspace, probably just because that's what I was taught to do. – dedded Oct 20 '14 at 0:21