Re: Factor, Extension

*To*: mathgroup at smc.vnet.net*Subject*: [mg113778] Re: Factor, Extension*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Fri, 12 Nov 2010 05:27:16 -0500 (EST)

The _coefficients_ of your polynomial are 1 and 2, in the domain of integers. Thus Sqrt[2] does _not_ appear in the polynomial. And so with Extension -> Automatic, there is no extension made. On 11/11/2010 6:10 AM, janos wrote: > Dear All, > > What is the meaning of the help of Factor: > > Factor[poly,Extension->Automatic] will extend the domain of > coefficients to include any algebraic numbers that appear in poly. =BB > > if > > Factor[x^2 - 2, Extension -> Automatic] > > does not seem to work in the same way as > > Factor[x^2 - 2, Extension -> Sqrt[2]] > > Thanks, > > J=E1nos > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305