Re: Bug in Reduce?
- To: mathgroup at smc.vnet.net
- Subject: [mg60425] Re: [mg60406] Bug in Reduce?
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Fri, 16 Sep 2005 03:49:05 -0400 (EDT)
- Reply-to: hanlonr at cox.net
- Sender: owner-wri-mathgroup at wolfram.com
$Version
5.2 for Mac OS X (June 20, 2005)
Reduce[{a c-b d==0,a d+b c==0},
{a,b,c,d},Reals]//Simplify
(a == 0 && b == 0) || (c == 0 && d == 0)
Bob Hanlon
>
> From: "Kennedy" <jack at realmode.com>
To: mathgroup at smc.vnet.net
> Date: 2005/09/15 Thu AM 05:16:26 EDT
> Subject: [mg60425] [mg60406] Bug in Reduce?
>
> The source of this apparent bug could be my misunderstanding of the
middle,
> "vars" parameter of Reduce, but it sure seems like the following output
> indicates that c must be 0 for my two equations to be satisfied, when in
> fact if a and b are both 0, c does not need to be 0.
>
> Regards,
> Jack
>
> In[1]:=
> Reduce[{a c - b d == 0, a d + b c == 0}, {a, b, c, d}, Reals] //
> FullSimplify
>
> Out[1]=
> c == 0 && (d == 0 || (a == 0 && b == 0))
>
> (version 5.1 for Windows)
>
>