Re: Re: rationalize numerator of quotient
- To: mathgroup at smc.vnet.net
- Subject: [mg81227] Re: [mg81208] Re: rationalize numerator of quotient
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Sun, 16 Sep 2007 04:09:02 -0400 (EDT)
- Organization: Mathematics & Statistics, Univ. of Mass./Amherst
- References: <29319569.1189724898261.JavaMail.root@eastrmwml14.mgt.cox.net> <fcdf9p$plc$1@smc.vnet.net> <200709150818.EAA28315@smc.vnet.net> <7EB64796-3E91-4153-8BFB-6717780343BE@mimuw.edu.pl>
- Reply-to: murray at math.umass.edu
There appears to be a little syntax error in RationalizeDenominator as
defined in the quoted message below. Namely, there a missing third
argument to PolynomialExtendedGCD, which should be t here.
Andrzej Kozlowski wrote:
> ... The factthat a fraction like:
>
> (2 + Sqrt[2])/(3 - 5*Sqrt[2])
>
>
> can be uniquely expressed in the form
>
> RationalizeDenominator[(2 + Sqrt[2])/(3 - 5*Sqrt[2]), Sqrt[2]]
>
> -(16/41) - (13*Sqrt[2])/41
>
> (where the function RationalizeDenominator is defined by
>
> RationalizeDenominator[f_, a_] := Block[{t},
> Numerator[f]*
> PolynomialExtendedGCD[Denominator[f] /. {a -> t},
> MinimalPolynomial[a, t]][[2, 1]] /. t -> a // Expand]
>
> )
> ....
--
Murray Eisenberg murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2859 (W)
710 North Pleasant Street fax 413 545-1801
Amherst, MA 01003-9305
- References:
- Re: rationalize numerator of quotient
- From: Peter Breitfeld <phbrf@t-online.de>
- Re: rationalize numerator of quotient