let tracage f df a b racine =
  let (x1, fx1, l1) = R.bissection ~max_iter:30. f a b in
  let (x2, fx2, l2) = R.fausse_position ~max_iter:30. f a b in
  let (x3, fx3, l3) = R.secante ~max_iter: 30. f a b in
  let (x4, fx4, l4) = R.newton ~max_iter: 30. f df b in
  let tab = [|l1; l2; l3; l4|] in
  Q.graphe tab colors racine;;


(*tracage f1 df1 0. 2. (sqrt 2.);;
tracage f2 df2 (-. 1.) 2. 0.;;
tracage f3 df3 (-. 1.) 2. 0.;;*)
tracage f4 df4 0. 8. (pi /. 2.);;