def computeDeriv(poly):
   result = []
   for i in range(len(poly)):
      if i==0:
         poly[i] = 0
      result.append(poly[i] * i)
   result.remove(0)
   if len(result) == 0 :
      result.append(0.0)
   return result
#print computeDeriv([20]) - it works from second exercise


def evaluatePoly(poly, x):
   index = 0
   for i in range(len(poly)):
       index += poly[i]*x**i
   return index
#print evaluatePoly([-12], 3.7) - it works fom first exercise




def povtor(poly, x_0) :

   proizvodnaia = computeDeriv(poly)
   funkcia_x0 =  evaluatePoly(poly, x_0)
   proizvodnaia_x0 = evaluatePoly(proizvodnaia, x_0)
   x_1 = x_0 - (funkcia_x0/proizvodnaia_x0)
   funkcia_x1 = evaluatePoly(poly, x_1)
   x_0 = x_1
   return funkcia_x1



def computeRoot(poly, x_0, epsilon):
   n = 0
   while abs(povtor(poly, x_0)) >= epsilon :
      n += 1
   return n
print computeRoot([1, 9, 8], -3, .01)