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Re: Simplify and Abs

• To: mathgroup at smc.vnet.net
• Subject: [mg54640] Re: [mg54602] Simplify and Abs
• From: Bob Hanlon <hanlonr at cox.net>
• Date: Fri, 25 Feb 2005 01:18:39 -0500 (EST)
• Reply-to: hanlonr at cox.net
• Sender: owner-wri-mathgroup at wolfram.com

FunctionExpand[Abs[p-1],p<1&&p>1/2]

1-p


Bob Hanlon

> 
> From: Simon Anders <simon.anders at uibk.ac.at>
To: mathgroup at smc.vnet.net
> Date: 2005/02/24 Thu AM 03:21:06 EST
> To: mathgroup at smc.vnet.net
> Subject: [mg54640] [mg54602] Simplify and Abs
> 
> Hi,
> 
> can it really be that this is already beyond Mathematica?
> 
>     In :=  FullSimplify[Abs[p - 1], p < 1 && p > 1/2]
> 
>     Out := Abs[-1 + p]
> 
> How do I make Matheamtica notice, that the assumptions constrain the 
> argument of Abs[] to positive values?
> 
> Any suggestions how to treat these kinds of problems? Specifically, I 
> have a list of products of absolute values of simple polynomials in p 
> and I know that p is in the interval [0,1].
> 
> I would like to know whether the polynomials have constant sign over the 
> interval so that the Abs[] can be removed. Can this be done automatically?
> 
> TIA
>    Simon
> 
> 

• Follow-Ups:
  • Re: Re: Simplify and Abs
    • From: Murray Eisenberg <murray@math.umass.edu>