# Approximation for Newton-Raphson Inverse Algorithm

 P: 1 I am attempting to make an initial approximation for the inverse algorithm (1/x) n = NUMBER TO INVERSE a = APPROXIMATION a = a*(2-(n*a)) 'a' gets closer to the actual result each time the algorithm is preformed The problem is finding the initial approximation. An exponential equation seems to fit the best a = .5^n The equation gets more accurate as n increases http://www09.wolframalpha.com/input/...%29-%28.5^x%29 I chose .5, because in binary, dividing by two is as simple as shifting to the right. Is there any other way to make a close approximation that is better than .5^n?