a=0;b=2;
    function y=f(x),
      y=x.^4-2
    endfunction;


    function y=dichotomie(epsilon)
       a1=min(a,b)
       b1=max(a,b)
       while (b1-a1)>epsilon,
         u=(a1+b1)/2
         if f(a1)*f(u)>0 then a1=u; else aremplacer; end,
       end
       y=[(a1+b1)/2,a1,b1,b1-a1]
     endfunction
