Re: simple Simplify[] question
- To: mathgroup at smc.vnet.net
- Subject: [mg19789] Re: simple Simplify[] question
- From: "Allan Hayes" <hay at haystack.demon.co.uk>
- Date: Fri, 17 Sep 1999 01:36:44 -0400
- References: <7rnkqn$emf@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Ulf Saalmann <us at atom.msi.se> wrote in message news:7rnkqn$emf at smc.vnet.net... > > > Hello, > > why gives Mathematica > 2 3/2 > Simplify[(a^2)^(3/2)] (a ) > > > and not > 3 > a > > and how to convince Mathematica to do it? > > > Thanks > Ulf (us at atom.msi.se) > Ulf, Mathematica works with complex numbers; and even with reals your reduction is not always true: Simplify[((-1)^2)^(3/2)] 1 (-1)^3 -1 However, we can tell Mathematica that a is positive, and then your reduction is true Simplify[(a^2)^(3/2), a > 0] a^3 Allan --------------------- Allan Hayes Mathematica Training and Consulting Leicester UK www.haystack.demon.co.uk hay at haystack.demon.co.uk Voice: +44 (0)116 271 4198 Fax: +44 (0)870 164 0565