Source
-2.5 5 setxrange
-0.5 3 setyrange

1 setxyrapport
60 setxunit
7.5 setborder
90 setangle_repere
-0.7 4 setxrange
-0.7 3 setyrange
1 1 settkstep
.5 .5 setsubtkstep
2 2 setmkstep

traceaxes
axesarrow

%unites
/f {setxvar
#rpn#   (7/10*x^2-41/20*x+37/20)
} def

/g {setxvar
#rpn#   5
} def


/M {0.5 0} def
/P {0.5 1} def
/N {3 0} def
/Q {3 2} def
/E {1.5 0} def
/F {1.5 0.35} def
/T {1.5 1.4} def
/Y1 {0 0.35} def
/Y2 {0 1.4} def

setTimesItalic
(O) O [1.8 dup] drtext
(x) 3.7 0 [1.8 dup]  drtext
(y) 0 2.7 [1.8 dup] ultext
(y) 0 0.35 [1.8 dup]  cltext
(y') 0 1.4 [1.8 dup] cltext
(P') T [1.5 dup] uctext
(P) 1.5 0.15 [1.5 dup] urtext

<latex>
$P_1$
</latex>
P [1.5 dup] dltexlabel

<latex>
$P_2$
</latex>
Q [1.5 dup] urtexlabel

gsave
pointilles
[M P] ligne
[N Q] ligne
[E F] ligne
[E T] ligne
[F Y1] ligne
[T Y2] ligne
grestore

[P F Q T] points
[P Q] ligne
gsave
   noir
   1 setlinewidth
   continu
0.15  3.5 {f} Courbe
grestore



<latex>
$x_1$
</latex>
0.5 0 [1.8 dup] dctexlabel

<latex>
$x_2$
</latex>
3 0 [1.8 dup] dctexlabel

<tex>
  $x$
</tex>
1.5 0 [1.8 dup] dctexlabel

<latex>
$f$
</latex>
%boxit
3.4 2.8 [1.8 dup] dctexlabel

<latex>
$\rm{Abb}.\,3$
</latex>
-1.3 1.2 [2.0 dup] ultexlabel