Graphique sous LateX

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[french]{babel}
\usepackage{tikz}
\usepackage{amsmath}

\begin{document}

\begin{tikzpicture}[x=1cm,y=1cm]
  \draw[thick,>=latex,->] (-1,0)--(8.5,0) node[below=4pt]{dim};
  \draw[thick,>=latex,->] (0,-1)--(0,5) node[left]{degré};
  \draw (1,4pt)--(1,-4pt) node[below]{$1$};
  \draw (7,4pt)--(7,-4pt) node[below]{$\mathrm{rang}(E)$};
  \draw (4pt,3.2)--(-4pt,3.2);
  \draw[fill] (0,0)--(1,2.8) circle(1.3pt) --(2.5,4) circle(1.3pt) --(4,4.5) circle(1.3pt) ;
  \draw[dotted] (4,4.5)--(6,4.2);
  \draw[fill] (6,4.2) -- (7,3.2) circle(1.3pt) node[above right]{$(\mathrm{rang}(E),\mathrm{deg}(E))$};
\end{tikzpicture}

\end{document}