(* exercice 1 *)
let rec pgcd a b = match b with
    | 0 -> a
#    | _ -> pgcd (b) (a mod b);;

print_int (pgcd 12 6);;

(* exercice 2*)
let rec dichotomie func a b epsilon = 
    let c = (a+.b)/.2. in
    if (b -. a) < epsilon then c 
    else if func(c) *. func(b) > 0. then dichotomie func c b epsilon
    else dichotomie func a c epsilon;;

print_float (dichotomie sin 1. 4. 0.001);;