18 setfontsize
-5 5 setxrange
-5 5 setyrange

/f {
   Tan
} def

/val 3.14 2 div def

40 setxunit
[1 1] {orange} Quadrillage
tracerepere
marks

gsave
   bleu
   1.75 setlinewidth
   val neg val {f} Courbe
   val neg pi add val pi add {f} Courbe
   val neg pi sub val pi sub {f} Courbe
grestore

setTimesItalic
   (O) O drtext

<tex>
$$
   y = \tan x
$$
</tex>

-3.5 2.5 [2 dup] cctexlabel