Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2003
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2003

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: imposing parameter assumptions

  • To: mathgroup at smc.vnet.net
  • Subject: [mg44196] Re: [mg44184] imposing parameter assumptions
  • From: "Peter Pein" <nospam at spam.no>
  • Date: Sun, 26 Oct 2003 00:41:50 -0400 (EDT)
  • References: <200310251026.GAA16281@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Simplify[Sign[a^-3], a < 0]
   -1

use FullSimplify for harder problems.

Peter Pein, Berlin
petsie at arcAND.de
replace && by || to write to me


----- Original Message -----
From: "drr7" <rondeau at uvic.ca>
To: mathgroup at smc.vnet.net
Subject: [mg44196] [mg44184] imposing parameter assumptions


> Simple question:  How do I impose assumptions on the sign of parameters in
> symbolic equations and then test for the sign of an expression. Example:
> suppose I want to test the sign of f[a]=a^-3 if a<0.  I tried combinations
> of Refine and Positive, but that does not seem to work for me.  What I am
> really trying to do is sign a long expression for a derivative.
> Thanks.
>
>


  • Prev by Date: RE: Extracting Terms From a List
  • Next by Date: AW: Re: Baffling Failure when plotting multiple curves.
  • Previous by thread: imposing parameter assumptions
  • Next by thread: Re: imposing parameter assumptions