%% auteur : 

-8.5 10.5 setxrange
-6.5 7.5 setyrange
25 setxunit
%50 setyunit

/quadrillagewidth[.7 .4 .1] def
[1 1 ]{.7 setgray} Quadrillage

1.2 setlinewidth
%0.5 0.5 setsubtkstep
traceaxes
ticks
%marks
%tracerepere
axesarrow
(-5) -5 0 [1.5 dup] dltext
(0) 0 0 [1.5 dup] dltext
(1) 1 0 [1.5 dup] dltext
(5) 5 0 [1.5 dup] dltext
(1) 0 1 [1.5 dup] cltext
(5) 0 5 [1.5 dup] cltext

/A{-7 -2} def
/B{-6 0} def
/C{-4 2} def
/D{-1 1} def
/E{0 2} def
/F{1 4} def
/G{4 6} def
/H{6 4} def
/I{6.5 2} def
/J{7 0} def
/K{8 -3} def
1.3 setlinewidth
[A .. B .. C .. D{right} .. E .. F .. G{right} .. H .. I .. J .. K] draw
%[A{60 dir} .. B .. C .. D{right} .. E .. F .. G{right} .. H .. I] (*->) draw
[A B C D E F G H I] points


setTimes
%(1) 1 0 [1.5 1.5] dtext
%(1) 0 1 [1.5 1.5] ltext
%(O) O [1.5 1.5] dltext

<tex>
$C_f$
</tex>
5.5 1.2 [1.5 dup] dctexlabel