Re: Simplify and Abs
- To: mathgroup at smc.vnet.net
- Subject: [mg54657] Re: Simplify and Abs
- From: "Dana" <delouis at bellsouth.net>
- Date: Fri, 25 Feb 2005 01:19:07 -0500 (EST)
- References: <cvk3fu$d6j$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
With version 5 Refine[Abs[p - 1], 1/2 < p < 1] 1 - p HTH -- Dana DeLouis "Simon Anders" <simon.anders at uibk.ac.at> wrote in message news:cvk3fu$d6j$1 at smc.vnet.net... > 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 >