%% auteur : Gilles Mora
-8 10 setxrange
-15 10 setyrange
1 1 setquadrillagestep
quadrillage
marks
tracerepere
/f {setxvar
-2 x sub 4 3 x sub div add
} def
{f} courbe
/g {setxvar
-2 x sub
} def
{g} courbe
/B{-7 5} def
setTimesItalic
(C) -7.7 7.2 drtext
(y=-x-2) B {-45} drtext