20 setxunit
-8 5 setxrange
-5 4 setyrange
quadrillage
tracerepere

/f {
   1 add dup mul neg 3 add
} def

{f} courbe
%{neg 1 sub} courbe

/fontsize 10 store

setTimesItalic
   (x) xmax 0 dltext
   (y) 0 ymax dltext

<tex>
$$
   y = -x^2 -2x + 2
$$
</tex>

-3.5 dup f ultexlabel