Re: Q: Factor with Polynominals?

*To*: mathgroup at smc.vnet.net*Subject*: [mg26703] Re: [mg26672] Q: Factor with Polynominals?*From*: BobHanlon at aol.com*Date*: Thu, 18 Jan 2001 00:57:11 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

I don't believe that there is a universal method; however, for the specific example given: expr = 3 x^2 + 3 y^2 + x + y^3 + y x^2; Simplify[expr /. x^2 -> (r^2-y^2)] /. r^2 -> (x^2 + y^2) x + (y + 3)*(x^2 + y^2) Bob Hanlon In a message dated 2001/1/17 1:18:10 AM, robert.schuerhuber at gmx.at writes: >i'd like to factor polynominals, e. g. if i have an exspression like > >3 x^2 + 3 y^2 + x + y^3 + y x^2, > >i'd like to get (i want to factor x^2+y^2): > >(x^2+y^2) (3 + y) + x. > >how can i achieve a result like this (also with other, more complicated >polynominals)? >