Integral in LaTeX (\int_{a}^{b})

Where it is used

Writes a definite integral sign with lower limit a and upper limit b.

Unlike \sum, the limits of \int sit to the side by default even in display math; add \limits, as in \int\limits_a^b, if your style requires them stacked. Put a thin space \, before the differential, as in \int_a^b f(x)\,dx, and some authors use an upright d via \mathrm{d}x. Multiple integrals have dedicated commands \iint and \iiint, which space the signs better than repeating \int. Contour integrals use \oint. For an evaluation bar after integration, write \Big|_a^b or \left. F(x) \right|_a^b.

Also listed under: Calculus & Analysis

Minimal compilable example

Paste this into an empty .tex file and compile it with pdfLaTeX, XeLaTeX or LuaLaTeX.

\documentclass{article}
\begin{document}
Integral: $\int_{a}^{b}$

\[ \int_{a}^{b} f(x)\,dx = F(b) - F(a) \]
\end{document}

Related symbols

• Limit\lim_{x \to \infty}
• Product\prod_{i=1}^{n}
• Infinity\infty
• Summation\sum_{i=1}^{n}
• Approximately Equal\approx
• N-th Root\sqrt[n]{x}

Frequently asked questions

How do I write Integral in LaTeX?

Type \int_{a}^{b} in math mode, for example $\int_{a}^{b} f(x)\,dx = F(b) - F(a)$. It works in plain LaTeX without loading any package.

Which package do I need for \int_{a}^{b}?

None. \int_{a}^{b} is part of standard LaTeX, so it compiles with nothing in the preamble but the document class.

Can I use \int_{a}^{b} in text mode, or only in math mode?

Only in math mode. Outside $...$ LaTeX stops with "Missing $ inserted", so write $\int_{a}^{b}$ in running text.