Simplifying polynomial and rounding problems

*To*: mathgroup at smc.vnet.net*Subject*: [mg82801] Simplifying polynomial and rounding problems*From*: "Isaac Martinez G." <isaac.martinez at sbcglobal.net>*Date*: Wed, 31 Oct 2007 06:14:15 -0500 (EST)

I am having problems with Mathematica precision/accuracy (or whatever you call it) I have the following expression A1=1.0000000000000002-0.6721560269293043s^2 - 0.32784397307069685s^4 Now when I factorize: There are a couple of (-1+s)(1+s) factors or something very close to 1. Like 0.999999999999999997+s I want to elliminate those factors but due to the fact that it is not really 1, but 0.999999999999999997 Mathematica does not always cancel those factors neither with A1/((-1.+s)(1.+s)) nor A1/((-1+s)(1+s)). How can I avoid the problem of 1 versus 0.999999999999999997 I am doing directional coupler design and I do need to elliminate some factors from an ABCD matrix where 5 to 6 decimal places is just fine in the last step. I have tried Factor[] Cancel[] FactorList[] but I always have this problem and it screws up my program. Sorry, I am new to Mathematica I am new to Mathematica.....