\begin{exercice}[Fonctions?]
Parmi les graphiques proposés, lesquels  correspondent à la représentation graphique d'une fonction?

\begin{tikzpicture}[scale=0.42,general]
            \draw [quadrillage] (-3,-2) grid (6,5);
            \draw (-1.5, 3.5) node[draw, circle, color=C1] {$a$};
            \axeX{-3}{6}{1}
            \axeY{-2}{5}{1}
            \origine
            \draw[color=B1prime, smooth, epais] plot coordinates{(-3,0)(-2,-1)(-1,-1)(0,0)(1,2)(2,3)(3,3.5)(4,1)(6,-1)};
            \draw[color=B1prime] (5,3) node {$\mathcal{C}_f$};
            \end{tikzpicture}
\hfill 
\begin{tikzpicture}[scale=0.42,general]
            \draw [quadrillage] (-3,-2) grid (6,5);
            \draw (-1.5, 3.5) node[draw, circle, color=C1] {$b$};
            \axeX{-3}{6}{1}
            \axeY{-2}{5}{1}
            \origine
            \draw[smooth,domain=1:6, color=B1prime, epais, samples=80] plot(\x,{--(sqrt(\x-1)+1)});
            \draw[smooth,domain=1:6, color=B1prime, epais, samples=80] plot(\x,{--(1-sqrt(\x-1))});
            \draw[color=B1prime] (3,3) node {$\mathcal{C}_g$};
            \end{tikzpicture}

\begin{tikzpicture}[scale=0.42,general]
           \draw [quadrillage] (-3,-2) grid (6,5);
            \draw (-1.5, 3.5) node[draw, circle, color=C1] {$c$};
            \axeX{-3}{6}{1}
            \axeY{-2}{5}{1}
            \origine
            \draw[smooth,domain=0.25:6, color=B1prime, epais] plot(\x,{--(1/\x)});
            \draw[smooth,domain=-3:-0.5, color=B1prime, epais] plot(\x,{--(1/\x)});
            \draw[color=B1prime] (5,3) node {$\mathcal{C}_h$};
            \end{tikzpicture}
\hfill
\begin{tikzpicture}[scale=0.42,general]
           \draw [quadrillage] (-3,-2) grid (6,5);
            \draw (-1.5, 3.5) node[draw, circle, color=C1] {$d$};
            \axeX{-3}{6}{1}
            \axeY{-2}{5}{1}
            \origine
            \draw[smooth,domain=1:6, color=B1prime, epais] plot(\x,{--(\x)-3)});
            \draw[color=B1prime] (5,3) node {$\mathcal{C}_k$};
            \end{tikzpicture}

\begin{tikzpicture}[scale=0.42,general]
            \draw [quadrillage] (-3,-2) grid (6,5);
              \draw (-1.5, 3.5) node[draw, circle, color=C1] {$e$};
            \axeX{-3}{6}{1}
            \axeY{-2}{5}{1}
            \origine
            \draw[ color=B1prime, epais](-3,2)--(6,2);
            \draw[color=B1prime] (5,3) node {$\mathcal{C}_m$};
            \end{tikzpicture}       
            \hfill   
    \begin{tikzpicture}[scale=0.42,general]
            \draw [quadrillage] (-3,-2) grid (6,5);
              \draw (-1.5, 3.5) node[draw, circle, color=C1] {$f$};
            \axeX{-3}{6}{1}
            \axeY{-2}{5}{1}
            \origine
            \draw[ color=B1prime, epais] (3,1) ellipse (1cm and 2cm);
            \draw[color=B1prime] (5,3) node {$\mathcal{C}_p$};
            \end{tikzpicture} 
\end{exercice}
