\begin{methode}[Lire des coordonnées\MethodeRefExercice*{2G2_E_lirecoordonnees}]


\exercice\label{2G2_M_lirecoordonnees}

\begin{enumerate}
\item Reproduire le repère $(O; I, J)$.
\item Lire les coordonnées du point $M$.
\item Placer le point $A$ de coordonnées $(-2;3)$.
\end{enumerate}

\begin{tikzpicture}[general, scale=0.3]
\draw [epais,->] (-4,0)--(10,0);
\draw [ ->, epais] (-3.333,-4)--(-0.667,4);
\draw (-2,0) node[below left] {$O$};
\draw (1,0) node {{\boldmath $+$}}; 
\draw (1,0) node[below] {$I$};
\draw (-1,3) node {{\boldmath $-$}}; 
\draw (-1,3) node[left] {$J$};
\draw (2,-3) node {{\boldmath $+$}}; 
\draw (2,-3) node[left] {$M$};
\end{tikzpicture}

\correction


\begin{tikzpicture}[general, scale=0.3]
\draw [quadrillage] (-7,-6)--(-1,12);
\draw [quadrillage] (-10,-6)--(-4,12);
\draw [quadrillage] (-10,3)--(-7,12);
\draw [quadrillage] (-1,-6)--(5,12);
\draw [quadrillage] (-10,-3)--(6,-3);
\draw [quadrillage] (-10,3)--(6,3);
\draw [quadrillage] (-10,6)--(6,6);
\draw [quadrillage] (-10,9)--(6,9);
\draw [quadrillage] (2,-6)--(6,6);
\draw [axe] (-4,-6)--(2,12);
 \draw [axe] (-10,0)--(6,0);
\draw (1,0) node {{\boldmath $+$}}; 
\draw (1,0) node[below] {$I$};
\draw (-1,3) node {{\boldmath $-$}}; 
\draw (-1,3) node[left] {$J$};
\draw (-2,0) node[below left] {$O$};
\draw [dashed, color=J1] (-3.5,-3)--(3.5,-3);;
\draw [color=J1,epais] (-3,-3)--(-2,0);
\draw [color=J1,epais] (4,0)--(-2,0);
\draw [dashed, color=J1] (4.167,0.5)--(2.833,-3.5);
\draw[color=J1] (-1.5,-1.5) node {\rotatebox{73.0}{{\boldmath $-OJ$}}}; 
\draw[color=J1] (1,0) node[above] {{\boldmath $2OI$}}; 
\draw[color=C1, epais] (-2,0)--(1,9);
\draw[color=C1, epais] (-2,0)--(-8,0);
\draw [dashed, color=C1] (-5.5,9)--(1.5,9);
\draw[color=C1] (-5,0) node[above] {{\boldmath $-2OI$}};
\draw[color=C1] (0.3,4.5) node {\rotatebox{73.0}{{\boldmath $3OJ$}}};
\draw [dashed, color=C1] (-4.83,9.5)--(-8.166,-0.5);
\draw (3,-3) node[below right] {$M$};
\draw (-5,9) node[above left] {$A$};
\end{tikzpicture}

Les coordonnées du point $M$ sont $(2;-1)$.
\end{methode}

\begin{remarque}
\begin{itemize}
 \item Les coordonnées d'un point sont toujours écrites dans le même ordre:\\ l'abscisse en premier et l'ordonnée ensuite.
\item Dans tout repère $(O;I,J)$, les coordonnées des points $O$, $I$ et  $J$ sont:
\begin{colitemize}{3}
\item $O(0;0)$
\item $I(1;0)$
\item $J(0;1)$
\end{colitemize}
\end{itemize}
\end{remarque}
