Answer to Question #218840 in Python for knikno

Question

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 

Answer 1

def my_sqrt(a):
	if a < 0:
		raise ValueError
	elif a == 0:
		return 0
	x = 1
	while True:
		y = (x + a/x) / 2.0
		if y == x:
			break
		x = y
	return x