Newsgroups: comp.sys.handhelds
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Re: Finding roots of Tertiary and above equations?
Message-ID: <1991May17.230122.21758@zoo.toronto.edu>
Date: Fri, 17 May 1991 23:01:22 GMT
References: <22117@shlump.nac.dec.com> <283322a6: 2812.1comp.sys.handhelds;1@hpcvbbs.UUCP>
Organization: U of Toronto Zoology

In article <283322a6:2812.1comp.sys.handhelds;1@hpcvbbs.UUCP> akcs.edlin@hpcvbbs.UUCP (Ed Linderman) writes:
>Umm, I'm quite sure quintics can ALL be solved with algebraic solutions,

There are formulas for cubics (3rd power) (slightly long) and quadrics
(4th power) (seriously long), but provably none for quintics and up.

Something like HP's numerical solver is often rather more useful in any
case.  Even with quadratics it's easy to find cases where the subtraction
operation in the formula nearly destroys the precision of the result,
while numerical techniques don't have that problem.
-- 
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  henry@zoo.toronto.edu  utzoo!henry