1 setxyrapport
25 setxunit
7.5 setborder
90 setangle_repere
-2 10 setxrange
-6 6 setyrange
1 1 settkstep
.5 .5 setsubtkstep
2 2 setmkstep
traceaxes
unites
/f {setxvar
#rpn#   0.5*(x-5)^2
} def
gsave
   bleu
   1 setlinewidth
   continu
   {f} courbe
grestore

gsave
noir
setTimesItalic

#latex#${\overrightarrow{i}}$
1 0 [1.5 1.5] dctexlabel
#latex#${\overrightarrow{j}}$
0 1 [1.5 1.5] cltexlabel

(O) 0 0 [2 2] dltext

grestore


/S {5 0} def

gsave
noir
setTimesItalic


(S) 5 0.25 [2 2] uctext
S point

grestore


#latex#$ \displaystyle{-\frac{b}{2a}}$
5 -0.25 [2 2] dctexlabel
%% adresse IP : 82.230.142.134