LaTeX/Basics

\documentclass{article} \begin{document} Hello world! \end{document}

\begin{document}
  Voici la fonction $\sin x$,
  la fonction \[\cos x=\sum_{k=0}^{\infty}\frac{(-1)^k}{(2k)!}x^{2k}\]
  et la fonction $\tan (x)$\ldots
\end{document}

va donner le résultat suivant :

Voici la fonction $\sin$, la fonction

$\cos x=\sum_{k=0}^{\infty}\frac{(-1)^k}{(2k)!}x^{2k}$

et la fonction tangente $\tan (x)$…

Spaces

"Whitespace" characters, such as blank or tab, are treated uniformly as "space" by LaTeX. Several consecutive whitespace characters are treated as one "space". Whitespace at the start of a line is generally ignored, and a single line break is treated as “whitespace.” An empty line between two lines of text defines the end of a paragraph. Several empty lines are treated the same as one empty line. The text below is an example. On the left hand side is the text from the input file, and on the right hand side is the formatted output.

It does not matter whether you enter one or several             spaces after a word. An empty line starts a new paragraph.

It does not matter whether you enter one or several spaces after a word. An empty line starts a new paragraph.