Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!think.com!linus!linus!linus!bs From: bs@linus.mitre.org (Robert D. Silverman) Newsgroups: comp.arch Subject: Re: sin(pi) (Was: Re: bizarre instructions) Message-ID: <1991Feb26.175315.9719@linus.mitre.org> Date: 26 Feb 91 17:53:15 GMT References: <15485@lanl.gov> <3028@charon.cwi.nl> Sender: news@linus.mitre.org (News Service) Organization: The MITRE Corporation, Bedford, MA 01730 Lines: 25 Nntp-Posting-Host: linus.mitre.org In article <3028@charon.cwi.nl> jurjen@cwi.nl (Jurjen NE Bos) writes: :jlg@lanl.gov (Jim Giles) writes: : :>Yes and no. Yes, most users expect sin(pi) to be zero. No, most :>users do _not_ expect sin(3.1415927) to be zero (or, whatever PI :>approximation you use). Any user who needs trig functions should be : :People owning a HP28 or HP48 know this. This calculator indeed delivers 0 for :sin(pi), and 0.0548036651488 for sin(3.14159265359). Note that the latter :value is correct to 12 digits. Huh??? sin(3.14159265359) = .05480366... ???? This value is so far off as to be unbelievable. When I punch sin(pi) into my HP I get -2.0676154e-13. I would not TRUST a calculator that actually returned 0.0 -- Bob Silverman #include Mitre Corporation, Bedford, MA 01730 "You can lead a horse's ass to knowledge, but you can't make him think" Brought to you by Super Global Mega Corp .com