%
% tkz-euclide (14/01/2011)
%
% Coding (utf8) Creator (TeX) Producer (pdfeTeX) 
% Author Alain Matthes
\input{tkzfctpreamble.ltx}

\begin{document}

\begin{tikzpicture}[scale=2.5]
   \tkzInit[xmin=-1,xmax=4,ymin=0,ymax=5]
   \tkzGrid
   \tkzAxeXY
   \tkzFct[domain = -.5:4]{ 4*x-x**2+4/(x**2+1)**2}
   \tkzFct[domain = -.5:4]{x-1+4/(x**2+1)**2}
   \tkzDrawAreafg[color=green,domain = 1:4]
   \tkzDrawAreafg[pattern=north west lines,domain = -.5:1]
   \tkzRep
   \tkzText(2.5,4.5){$C_f$}
   \tkzText(2.5,1){$C_g$}
\end{tikzpicture}%

\end{document} 
