-2 6.01 setxrange
-2 4 setyrange

/xmarkstyle {dltext} def
/ymarkstyle {dltext} def

quadrillage
traceaxes
marks
0 ymark

/A {0 3} def
/B {3 0} def

/f {
   setxvar
   2 x mul 3 add
   x neg Exp mul
} def

A B droite

1.2 setlinewidth
{f} courbe

setTimesItalic
   (C) -1.3 dup f ultext
   (A) A urtext
   (B) B urtext
setSymbol
   (D) -.5 3.5 urtext