Newton’s Method in Python
def sqrt(n):
"""
This method calculates the square root
of a value using Newton's method to an
accuracy of within sigma.
"""
sigma = 0.0001
# The first guess is n / 2
# (which only works when n is 4)
guess = n / 2
while abs(n - guess * guess) > sigma:
# Compute the quotient
quotient = n / guess
# Average the quotient and the current guess
guess = (quotient + guess) / 2
return guess
