Re: Mathematica Question

*To*: mathgroup at smc.vnet.net*Subject*: [mg66404] Re: [mg66358] Mathematica Question*From*: "Chris Chiasson" <chris at chiasson.name>*Date*: Thu, 11 May 2006 02:16:31 -0400 (EDT)*References*: <200605101034.GAA21918@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In[2]:= Positive[x^2 + y] Out[2]= Positive[x^2 + y] In[3]:= Refine[%, x > 0 && y > 0] Out[3]= True In[4]:= Information["$Assumptions", LongForm -> False] "$Assumptions is the default setting \ for the Assumptions option used in \ such functions as Simplify, Refine \ and Integrate."*Button[More\[Ellipsis], ButtonData :> "$Assumptions", Active -> True, ButtonStyle -> "RefGuideLink"] In[5]:= $Assumptions = {z > 0} Out[5]= {z > 0} In[6]:= Positive[z] Out[6]= Positive[z] In[7]:= Refine[Positive[z]] Out[7]= True On 5/10/06, Bharat Bhole <bbhole at gmail.com> wrote: > Hello: > > Is there a way in Mathematica to check whether an algebraic expression is > positive or negative, and a way to specify conditions on the variables in > the expression? For example, is there a way to check whether x^2 is positive > for any real x? I want to check this for a complicated > expression...basically the sign of the second derivative of a function. > > Thank you very much for your help. > > Bharat. > > > -- http://chris.chiasson.name/

**References**:**Mathematica Question***From:*"Bharat Bhole" <bbhole@gmail.com>