Re: constants

*To*: mathgroup at smc.vnet.net*Subject*: [mg100204] Re: constants*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Thu, 28 May 2009 04:27:34 -0400 (EDT)

On 5/27/09 at 4:07 AM, olfa.mraihi at yahoo.fr (olfa) wrote: >Hi mathematica community I have to Reduce[{x + a*z/(1 - d) == y + >a*w/(1 - d)] I need to tell mathematica that a and d are constants >how ? Why do you think you need to have a means to make a and d constant? What are you expecting Reduce to do here. If you replace a with 1 and d with 0 the relationship becomes x + z == y + w which cannot be reduced further without more information. The same is true regardless of what constant values are chosen for a and d with the one exception of d = 1.