The method in question was known for millennia before Newton, it is believed to be known to Babylonians: https://en.m.wikipedia.org/wiki/Methods_of_computing_s

The method in question was known for millennia before Newton, it is believed to be known to Babylonians: https://en.m.wikipedia.org/wiki/Methods_of_computing_square_roots https://en.m.wikipedia.org/wiki/Methods_of_computing_square_...