square_root.py

#Newton's method of successive approximations says that whenever we have a
#guess y for the value of the square root of a number x, we can get a
#better guess (one closer to the actual square root) by averaging y with x/y. If we do this over and over, we should be able to get a very accurate guess.

#You have to write a script that asks the user for a positive number and
#then compute the square root with a maximum error of 0.1.
#You then print out your answer to the user.



# x = int(input ("Give me a positive number: "))
# y = 0.1
#
# while y < (x / 2):
#     if (y ** 2) <= (x - .01):
#         y += 0.1
#     else:
#         break
#
# print("The square root of {} is {}.".format(x, round(y, 3)))


# x = input ("Give me number: ")
# y = (int(x)**0.5)
# print (y)


num = int(input ("I need a positive number: "))
tolerance = 0.1
y = 0.1

while y < (num / 2):
    if y**2 < (num - tolerance):
        y += 0.1
    else:
        break

print("The square root of {} is {}.".format(num, round(y, 3)))