def f1(x):
  return x**3+x-1

def f2(x):
  return 3*x**2+1

def newton(f1, f2, n):
  k = 4
  L = [k]
  for i in range(1, n):
    k = k - (f1(k))/(f2(k))
    L.append(k)
  return L