Re: solve and Abs
- To: mathgroup at smc.vnet.net
- Subject: [mg69397] Re: solve and Abs
- From: Peter Pein <petsie at dordos.net>
- Date: Sun, 10 Sep 2006 07:20:34 -0400 (EDT)
- References: <edtrmv$le6$1@smc.vnet.net>
Richard J. Fateman schrieb: > Is there a reason (in 5.1) for Solve[x-Abs[x]==0,x] to return {{}}? > This supposedly means all variables can have all possible values. > > Reduce does better. > Hello, the result {{}} means that Solve did not find values for x, which fulfill the equation without "special conditions". The help browser tells us: "Solve gives generic solutions only. It discards solutions that are valid only when the parameters satisfy special conditions. Reduce gives the complete set of solutions. " The special condition in this case is obviously x>=0. Greetings, Peter
- Follow-Ups:
- Re: Re: solve and Abs
- From: Murray Eisenberg <murray@math.umass.edu>
- Re: Re: solve and Abs