Présentation de cardioide_03.jps

-1.5 1.5 setxrange
-1.5 1.5 setyrange
jpegmode
/A {-1 0} def
/cerc {O 1} def
/alpha 60 def

/m {alpha cerc cpoint} def
/M {A O m m perp orthoproj} def

cerc cercle
[A m M] points

gsave
   mixte
   O m 1 trait
   A M 1 trait
   m M 1.48 trait
grestore
/@ngledr@it 4 def

O m M angledroit
A M m angledroit

/X {settvar
    t Cos t Sin dup mul sub
} def
/Y {settvar
    t Sin t Cos 1 add mul
} def

0  2 pi mul settrange

/Y' {settvar
    t Cos dup dup mul add t Sin dup mul sub
} def
/X' {settvar
    t Cos 2 mul 1 add t Sin mul neg
} def

continu

/dessin {
   tracerepere
   marks
   1 dict begin
   1.5 setlinewidth
   gsave
      bleu
      {X} {Y} courbeparam
   grestore
   end
} def

dessin
 
setTimesItalic
   (A) -1.15 -.05 dtext
   (O) O drtext
   (m) m dtext
   (M) M utext


pi 3 div (X) (Y) ptangente
0 (X) (Y) ptangente
pi -3 div (X) (Y) ptangente

.8 settailletangente
pi 2 mul 3 div (X) (Y) ptangente
pi -2 mul 3 div (X) (Y) ptangente