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

\begin{document}

\begin{tikzpicture}
\tkzInit[xmin=-1,xmax=1,ymin=-1.8,ymax=1.2,xstep=0.1,ystep=0.2]
\tkzGrid
\tkzAxeXY
\tkzFct[samples = 400, line width=4pt, color = red,opacity=.5](-1---1){1/(1+8*\x*\x)}
 \tkzFct[smooth,samples = 400, line width=1pt, color = blue,domain =-1:1]%
{1.0+((((((((((((((((((((
                          8140.04642)*\x
                            +0.01544)*\x
                        -32356.67279)*\x
                            -0.05562)*\x
                        +54061.87086)*\x
                            +0.08097)*\x
                        -49850.83249)*\x
                            -0.05934)*\x
                        +28118.29594)*\x
                            +0.02540)*\x
                        -10240.01777)*\x
                            -0.00580)*\x
                         +2516.04640)*\x
                            +0.00071)*\x
                          -444.23476)*\x
                            -0.00004)*\x
                           +62.60245)*\x
                            +0.00000)*\x
                            -7.99142)*\x
                            -0.00000)*\x}
 \tkzSetUpPoint[size=16,color=black,fill=yellow]
 \foreach \v in {-1,-0.8,---.,1}{\tkzDefPointByFct[draw](\v)}
\end{tikzpicture}

\end{document} 
