It is equivalent when applied to the function f(a) = a^(1/2) - x. Also, one needs to divide by 2 since if a is the square root of x, then a+x/a = a + a = 2a. n

It is equivalent when applied to the function f(a) = a^(1/2) - x. Also, one needs to divide by 2 since if a is the square root of x, then a+x/a = a + a = 2a. n-th roots are not quite as nice, but still work fairly simply: ((n-1) a + x/a^(n-1) )/n You can see that the fixed point (a = nth root of x) works out as it should.