-1 4.5 setxrange
-1.2 1.2 setyrange

1 setxyrapport
60 setxunit
7.5 setborder
90 setangle_repere
-1 4 setxrange
-1 1 setyrange

traceaxes
axesarrow
1 xtick
2 xtick
3 xtick

/A {3 -1} def
/B {3 1} def

/f {setxvar
#rpn#   0.3*(-x^2+2.4*x-36/25)+0.5
} def

gsave
   noir
   0.5 setlinewidth
   continu
-1  3.5 {f} Courbe
grestore

gsave
0.5 setlinewidth
pointilles 
[A B] ligne 
grestore

[1.2 0] points
gsave
pointilles 
[1.2 0 1.2 0.5] ligne
grestore

<latex>
$\frac{-b}{2a}$
</latex>
1.2 0 [1.3 dup] dctexlabel

<latex>
$3$
</latex>
3 0 [1.3 dup] drtexlabel

<latex>
$m-1<0, \Delta>0$
</latex>
2.25 -0.4 [1.3 dup] dltexlabel

<latex>
$\frac{-b}{2a}<3, f(3)\leq 0$
</latex>
2.2 -0.7 [1.3 dup] dltexlabel