%% auteur : Gilles Mora

120 setxunit
7.5 setborder
90 setangle_repere
-0.5 3.5 setxrange
-0.5 4 setyrange
1 1 settkstep
.5 .5 setsubtkstep
1 1 setmkstep
14 setfontsize
/quadrillagewidth[.7 .4 .1] def
[1 1 .5 .5 .5 .5]{.7 setgray} Quadrillage
/ymarkstyle {cltext} def
ticks
subticks
ymarks
xmarks

traceaxes
axesarrow
unites
/f {setxvar
#rpn#  0.5*(x+2/x) 
} def
gsave
   1 setlinewidth
      0.1 6 {f} Courbe
grestore

 /g {setxvar
#rpn#  x 
} def
gsave
   1 setlinewidth
      0 6 {g} Courbe
grestore


<tex>
$y=x$ 
</tex>
3.1 3.4 [2 dup] {45} dctexlabel

<tex>
$y=f(x)$ 
</tex>
3.1 2.1 [2 dup] {25} dctexlabel



<tex>
O 
</tex>
0 0 [1.5 dup]  dltexlabel