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Re: Assumptions i Mathematica...

• To: mathgroup at smc.vnet.net
• Subject: [mg25709] Re: [mg25660] Assumptions i Mathematica...
• From: Tomas Garza <tgarza01 at prodigy.net.mx>
• Date: Thu, 19 Oct 2000 04:35:33 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

It depends on what use you're going to give the restrictions or 
assumptions. If you define a function f[x] you might as well use 
conditions:  "lhs := rhs /; test is a definition to be used only if 
test yields True" (see the on-line Help Browser under "Condition"). For 
example

f[x_]:=  Sin[x]/; x>=0

says that f[x] is defined only for nonnegative x.

Tomas Garza
Mexico City



"Jes Hansen" <Whammer.antispam at post9.tele.dk> wrote:

> Hi, I'm quite new at this, and I havn't been able to figure out how to 
tell
> Mathematica to assume that a variable, x, is positive. I have a 
function,
> f(x), where I only want to consider positive values of x. I'm using 
version
> 3.0.