-3 7 setxrange
-7 5 setyrange
10 setfontsize
/arrowscale {.7 dup} def
quadrillage
.7 setlinewidth
traceaxes
axesarrow
unites

/f {2 sub dup mul neg 3 add} def

1 setlinewidth
-1 5 {f} Courbe

setTimesItalic
   (O) O dltext
   (x) xmax 0 (-5 0) dltext
   (y) 0 ymax dltext

<tex>
$\vec \imath $
</tex>
.5 0 dctexlabel

<tex>
$\vec \jmath $
</tex>
0 .5 cltexlabel