Re: About Reduce and Mod
- To: mathgroup at smc.vnet.net
- Subject: [mg96926] Re: About Reduce and Mod
- From: dh <dh at metrohm.com>
- Date: Fri, 27 Feb 2009 06:14:33 -0500 (EST)
- References: <go63mv$psm$1@smc.vnet.net>
Hi,
Mathematica calculates by default with complex number. You must tell it that you
are looking for real numbers by e.g. specifying a domain:
Reduce[{Mod[x, 5] == Mod[xP, 5], 0 <= xP < 5}, {xP}, Reals,
Backsubstitution -> True]
hope this helps, Daniel
olfa wrote:
> Hi Mathematica community,
> I have this input: Reduce[{Mod[x, 5] == Mod[xP, 5], 0 <= xP < 5},
> {xP}, Backsubstitution -> True]
> Mathematicas gives me this output:0 <= Re[Mod[x, 5]] < 5 && Im[Mod[x,
> 5]] == 0 && xP == Mod[x, 5]
> 1)but why there is 0 <= Re[Mod[x, 5]] < 5 && Im[Mod[x, 5]] == 0 as
> part of the output ?
> 2) and how could I eliminate it (by adding something in reduce for
> example) because all that I want is only this output xP == Mod[x, 5]?
>
> thank you very much.
>