a more precise distance algorithm

[ravas]

On Monday, May 25, 2015 at 8:11:25 PM UTC-7, Steven D'Aprano wrote:
> Let's compare three methods. 
> ...
> which shows that:
> 
> (1) It's not hard to find mismatches;
> (2) It's not obvious which of the three methods is more accurate.

Thank you; that is very helpful!

I'm curious: what about the sqrt() function being last is detrimental?
>From a point of ignorance it seems like we are just producing errors sooner, 
and then multiplying them, with this alternative method.