sqrt

import math
def bisection(number):
   a = 1.0
   b = number/2.0
   mid = (a+b)/2
   aprox = number -mid*mid
   while math.fabs(aprox) > 0.0001:
      if aprox < 0:
         b = mid
      else:
         a = mid
      mid = (a+b)/2.0
      aprox = number -mid*mid
   return mid

def heron(number):
   aprox = 1.0
   aprox = (aprox +number)/2.0
   while math.fabs(number -aprox*aprox) >0.0001:
      aprox = (aprox +number/aprox)/2.0
   return aprox

def newton(number):
   aprox = 1.0
   diff = aprox -number
   while math.fabs(diff) > 0.0001:
      aprox = aprox -(diff)/(2*aprox)
      diff = aprox*aprox -number
   return aprox