Integral - Latex — Robin Pourtaud

Integral sign

Integral sign is present everywhere in mathematics.

In Latex, to display an integral, it is possible to use the command \int.

\int_{a}^{b}f(x)dx

This gives :

$\int_{a}^{b}f(x)dx$

Multi-line integral

It is possible that you will find an integral written on a line as \int_{a}^{b}f(x)dx. You can force the display of the integral (“in large”) on several lines by using the following command :

\displaystyle \int_{a}^{b}f(x)dx

This gives :

$\displaystyle \int_{a}^{b}f(x)dx$

Other integral signs

You can double, triple, etc. the integral sign :

Latex	Result
\int	$\int$
\iint	$\iint$
\iiint	$\iiint$

An \oint integral sign is also possible.

Latex	Result
\oint	$\oint$
\oiiint	$\oiiint$
\oiiint	$\oiiint$

These integral signs “with a circle” are generally used to denote an integral on a closed curve. For exemple an integral on a circle $C$ . $\oint_C f(x) dx = \int_0^{2\pi} f(x)dx$ Less approximations here : Contour Integration This is only a notation, integral rules still apply here. For exemple, you can check the Maxwells equations.