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.