Sums, integrals and function names in LaTeX
Write \sum_{i=1}^{n} or \int_{0}^{1} in math mode: the part after _ is the lower limit and the part after ^ the upper one. In a display, the limits of a sum go below and above it.
Sums, products and integrals
Big operators take their limits with _ and ^. In a display formula the limits of \sum, \prod, \bigcup and the like go under and over the symbol; in running text they go to the side, so the line spacing stays even. Integral limits always go to the side.
Big operators in a display
\sum_{i=1}^{n} i = \frac{n(n+1)}{2} \qquad
\prod_{k=1}^{44} \frac{k}{k+1} = \frac{1}{45} \qquad
\int_{0}^{\infty} e^{-x}\,dx = 1 \qquad
\bigcup_{i \in I} A_i\limits after an operator forces the limits above and below, \nolimits puts them to the side. \substack stacks several conditions under a sum.
Limits placement and stacked conditions
\int\limits_{0}^{1} f \qquad \sum\nolimits_{i} a_i \qquad
\sum_{\substack{0 \le i \le n \\ i \ne 44}} a_i \qquad \oint_C \mathbf{F} \cdot d\mathbf{r}
\qquad \iint_D f \, dAFunction names
Function names such as sin, log and max are set upright, with the right spacing, when you use their commands. Typing sin x without the backslash gives italic letters s·i·n, which reads as a product.
Function names
\sin^2 x + \cos^2 x = 1 \qquad \log_2 44 \approx 5.46 \qquad
\lim_{x \to 0} \frac{\sin x}{x} = 1 \qquad \max_{1 \le i \le n} x_i \qquad \det AFor a name that has no command, use \operatorname{..} in a formula, or define it once in the preamble with \DeclareMathOperator. The starred forms put limits under the name, as for \lim.
Your own operator names
\documentclass{article}
\usepackage{amsmath}
\DeclareMathOperator{\tr}{tr}
\DeclareMathOperator*{\argmax}{arg\,max}
\begin{document}
The trace is $\tr A$, and
\[ \hat\theta = \argmax_{\theta} L(\theta), \qquad \operatorname{rank} A = 44. \]
\end{document}All big operators
Click a copy button to copy the command.
\sum\prod\int\iint\iiint\oint\oiint\oiiint\bigodot\bigoplus\bigotimes\bigcup\biguplus\bigsqcup\bigcap\coprod\bigwedge\bigvee\bigdot\bigplus\bigtimes\intop\smallint
All function names
\sin\cos\tan\cot\sec\csc\arcsin\arccos\arctan\sinh\cosh\tanh\coth\ln\log\lg\lim\limsup\liminf\hom\det\exp\deg\gcd\lcm\dim\ker\arg\Pr\max\min\argmax\argmin\sup\inf
What does not work
\bigoplus, \bigotimes, \bigodot and \bigcap work with limits; in earlier versions they stopped the whole document (see when the document does not typeset).
Big circled operators and intersections
\bigoplus_{i=1}^{n} V_i \qquad \bigcap_{k} U_k \qquad \bigotimes_{j} W_jRelated pages
- Math basics and equations and alignment.
- Operators for the small forms such as ∪ and ⊕.
\DeclareMathOperator,\substackand the integral variants come from amsmath; its manual is on CTAN (amsmath).
Questions and answers
How do I put the limits of a sum above and below in inline math?
Write \sum\limits_{i=1}^{n}. Use it sparingly: tall inline formulas push the lines of the paragraph apart.
How do I write a double or triple integral?
Use \iint or \iiint, which are spaced better than two \int in a row. \oint gives a contour integral.
How do I write argmax in LaTeX?
Put \DeclareMathOperator*{\argmax}{arg\,max} in the preamble, then write \argmax_{x} f(x). Without the definition, \operatorname*{arg\,max}_{x} does the same in one place.
Every example on this page is typeset by Scissor LaTeX when the site is built. Last updated 2026-11-06.