Answer to Question #192525 in Python for Davis Appiah Adjei

Question

Part 1

Encapsulate the following Python code from Section 7.5 in a function named my_sqrt that takes a as a parameter, chooses a starting value for x, and returns an estimate of the square root of a. 

while True:

   y = (x + a/x) / 2.0

   if y == x:

     break

   x = y 

Part 2

Write a function named test_sqrt that prints a table like the following using a while loop, where "diff" is the absolute value of the difference between my_sqrt(a) and math.sqrt(a). 

Answer 1

import math


def my_sqrt(a):


	if a == 0:
		return 0
	x = 1
	while True:
		y = (x + a/x) / 2.0
		if y == x:
			break
		x = y
	return y




def test_sqrt():


	k = 0
	while k < 20:
		my = my_sqrt(k)
		std = math.sqrt(k)
		diff = abs(my - std)
		s = 'a = {0} | my_sqrt(a) = {1} | math.sqrt(a) = {2} | diff = {3}'.format(k, my, std, diff)
		print(s)
		k += 1


test_sqrt()