Newsgroups: comp.arch
Path: utzoo!utgpu!watserv1!watdragon!rose!ccplumb
From: ccplumb@rose.uwaterloo.ca (Colin Plumb)
Subject: Re: sin(pi) (Was: Re: bizarre instructions)
Message-ID: <1991Feb27.001143.5526@watdragon.waterloo.edu>
Sender: daemon@watdragon.waterloo.edu (Owner of Many System Processes)
Organization: University of Waterloo
References: <KHB.91Feb21102723@chiba.Eng.Sun.COM> <15485@lanl.gov> <3028@charon.cwi.nl> <1991Feb26.175315.9719@linus.mitre.org>
Date: Wed, 27 Feb 1991 00:11:43 GMT
Lines: 16

bs@linus.mitre.org (Robert D. Silverman) wrote:
>In article <3028@charon.cwi.nl> jurjen@cwi.nl (Jurjen NE Bos) writes:
>: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

The HP 28 and 48 have a symbolic "pi" symbol that they propagate, only
converting to floating point when necessary.  The trig functions all
accept it, returning 0.5 for sin(pi/6), etc.
-- 
	-Colin
