# Formulas using MathML and LaTeXMathML

## Error message

Deprecated function: The each() function is deprecated. This message will be suppressed on further calls in book_prev() (line 775 of /var/www/drupal-7.37/modules/book/book.module).

In order to use MathML successfully, one may use one of the following most common software configurations:

• Firefox 1.9 or higher with fonts installed. The installation process is described at
Mozilla site
$x^2$
$\displaystyle{\int_{-\infty}^\infty e^{-\frac{t^2}{2}}\,dt=\sqrt{2\pi}.$