Reduce Question
- To: mathgroup at smc.vnet.net
- Subject: [mg92898] Reduce Question
- From: Chris Metcalf <metcalcj at hotmail.com>
- Date: Fri, 17 Oct 2008 05:24:41 -0400 (EDT)
Hi My question concerns how mathematica arrives at the following result: In:= Reduce[ Root[8 m - 16 m #1 - 8 x #1 + 2 m #1^2 + 16 m #1^3 + 8 x #1^3 - 7 m #1^4 - 8 m #1^5 - 4 x #1^5 + 3 m #1^6 + 2 m #1^7 + x #1^7 & 2] < (1/2) (((-((m + x)/m)) + (8 + ((m + x))^2/m^2))) && m > 0 && x > 0] Out:= m > 0 && x > 0 I think that the answer is the CylindricalDecomposition algorithm (since the same input into that function arrives at the same conclusion) but I am not sure what that algorithm is doing beyond the broadest terms. Specifically my questions are: (1) is there any way to replicate this conclusion by hand (that is to derive that the one expression is less than the other)? (2) if not is there a satisfactory way to describe how the conclusion was reached? I appreciate your attention. Thanks Chris Metcalf _________________________________________________________________