vettore delle iterate
   1  1.000000000000000e+00
   2  5.378828427399902e-01
   3  4.456167485265452e-01
   4  4.428567246451099e-01
   5  4.428544010040325e-01
   6  4.428544010023886e-01
 
 vettore dello step
 1.718281828459046e+00
 2.502604917015276e-01
 7.069671237855291e-03
 5.941896962347037e-06
 4.203748460440693e-12