Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!uxc.cso.uiuc.edu!uxc.cso.uiuc.edu!ux1.cso.uiuc.edu!uxe.cso.uiuc.edu!mcdonald
From: mcdonald@uxe.cso.uiuc.edu
Newsgroups: comp.sys.mac
Subject: Re: Bug in EXCEL v. 2.2, and a flame
Message-ID: <46100320@uxe.cso.uiuc.edu>
Date: 1 Aug 89 14:55:00 GMT
References: <4134@utastro.UUCP>
Lines: 23
Nf-ID: #R:utastro.UUCP:4134:uxe.cso.uiuc.edu:46100320:000:600
Nf-From: uxe.cso.uiuc.edu!mcdonald    Aug  1 09:55:00 1989



>Funny, your Sharp and my HP must hail from a common genetic origin.  My
>HP-28C give SQRT(.999975) as 0.999987499922; upon hitting the "x^2" key,

>Anybody else?

Sure, I'll bite. This is by hand, using the power series:


sqrt(1-.000025) = 1 
                  -.0000125
                  -7.8125*10-11
                  -9.765625*10-16
                  -1.52587890625*10-20
                  -2.670288...*10-25

                = .999997499218740234222409....


which is subject only to errors in my hand addition, not algorithm bugs.

P.S. I don't do hand addition very often - CAVEAT EMPTOR!