On considère une fonction $f$ dont la courbe repr\'esentative est la suivante :

\begin{center}
\begin{tikzpicture}
\node[inner sep = 1em, outer sep = 0pt, fill = white] (img) {
\begin{tikzpicture}[yscale=0.15]
\draw[gray,dashed] (0,-25) grid[xstep=1,ystep=5] (10,5);
\draw[->,>=stealth',thick] (0,-25) -- (0,5);
\draw[->,>=stealth',thick] (0,0) -- (10,0);
\foreach\x in {1,2,3,4,5,6,7,8,9}
{
	\draw[thick] (\x,0.6) -- (\x,-0.6) node[below] {\x};
}
\foreach\y in {-25,-20,-15,-10,-5,5}
{
	\draw[thick] (0.1,\y) -- (-0.1,\y) node[left] {$\y$};
}
\draw[very thick,cyan] plot[domain=0.01:10,samples=100] (\x,{\x*\x*ln(\x)-3*\x*\x+5*\x-1});
\end{tikzpicture}};
\drawshadow{img}{black}
\end{tikzpicture}
\end{center}

Placer approximativement son point d'inflexion et préciser les intervalles où $f$ est concave et convexe.

