\documentclass[a4paper,12pt]{book}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{lmodern}
\usepackage[francais]{babel}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{fourier}
\usepackage[scaled=0.875]{helvet} 
\renewcommand{\ttdefault}{lmtt} 
\usepackage{amsmath,amssymb,makeidx}
\usepackage[normalem]{ulem}
\usepackage{fancybox,graphics,graphicx}
\usepackage{graphicx}
\usepackage{tabularx}
\usepackage{pifont}
\usepackage{ulem}
\usepackage{dcolumn}
\usepackage{textcomp}
\usepackage{ifthen}
\usepackage{diagbox}
\usepackage{scratch}
\usepackage{enumitem}
\usepackage{tabularx}
\usepackage{multirow}
\usepackage{lscape}
\newcommand{\euro}{\eurologo{}}
\newcommand{\grasoul}[1]{\underline{\textbf{#1 }}}
\newcommand{\red}[1]{{\color{red}#1}}
\newcommand{\green}[1]{{\color{green}#1}}
\newcommand{\blue}[1]{{\color{blue}#1}}
\newtheorem{df}{\grasoul{\red{DÉFINITION }}}
\newtheorem{prop}{\grasoul{\red{PROPRIÉTÉ }}}
\newtheorem{thm}{\grasoul{\red{THÉORÈME }}}
\newtheorem{rmq}{\grasoul{\green{Remarque }}}
\newtheorem{ex}{\grasoul{\blue{Exemple}}}
%Tapuscrit : leonidasse DIMANCHE
\usepackage{pstricks,pst-plot,pst-text,pst-tree,pstricks-add}
\usepackage[left=2cm, right=2cm, top=2cm, bottom=2cm]{geometry}
\usepackage{tikz}
\usetikzlibrary{patterns}
\usepackage{fancyhdr}
\newcommand{\vect}[1]{\overrightarrow{\,\mathstrut#1\,}}
\newcommand{\E}[1]{\mathbb{#1}}
\newcommand{\C}[1]{\mathcal{#1}}
\newcommand{\F}[1]{\mathfrak{#1}}
\newcommand{\N}[1]{\mathnormal{#1}}

\renewcommand{\theenumi}{\textbf{\arabic{enumi}}}
\renewcommand{\labelenumi}{\textbf{\theenumi.}}
\renewcommand{\theenumii}{\textbf{\alph{enumii}}}
\renewcommand{\labelenumii}{\textbf{\theenumii.}}
\def\Oij{$\left(\text{O}~;~\vect{\imath},~\vect{\jmath}\right)$}
\def\Oijk{$\left(\text{O}~;~\vect{\imath},~\vect{\jmath},~\vect{k}\right)$}
\def\Ouv{$\left(\text{O}~;~\vect{u},~\vect{v}\right)$}

\usepackage{hyperref}

\usepackage[np]{numprint}

\title{\textbf{Cours de quatrième}}
\author{L DIMANCHE}

\begin{document}

\maketitle
\tableofcontents

%Chapitre 1
\chapter{}
\section*{I)}


\end{document}
