Source
28.45 setxunit
90 setangle_repere
-2 5 setxrange
-4 6 setyrange
2 2 settkstep
ticks
marks
traceaxes
axesarrow
unites
/a 2.5 def
/f {setxvar
#rpn#   2*x^2-3*x-2
} def
/g {setxvar
#rpn#   2*x^2-7*x+4
} def
gsave
   bleu
   1 setlinewidth
   continu
   {f} courbe
grestore
gsave
   rouge
   1 setlinewidth
   mixte
   {g} courbe
grestore
setTimesItalic 
   (f)  2.7 dup f exch -0.5 add exch [1.5 dup] urtext
   (g)  3.5 dup g exch 0.2 add exch 0.5 add [1.5 dup] urtext
   (C)  -1 dup f [1.5 dup] urtext
   (C')  0.5 dup g [1.5 dup] urtext
[3 4 div dup dup f exch dup f exch 1 add exch 1 add ] (->) ligne 
<latex>
$\overrightarrow{i}+\overrightarrow{j}$
</latex>
3 4 div dup f exch 0.5 add exch 0 add [1.5 dup] crtexlabel
[a dup dup f exch dup f exch 1 add exch 1 add ] (->) ligne 
<latex>
$\overrightarrow{i}+\overrightarrow{j}$
</latex>
a dup f exch 0.5 add exch 0 add [1.5 dup] crtexlabel