Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2005
*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 2005

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

Search the Archive

Re: Complex numbers in Mathematica

  • To: mathgroup at smc.vnet.net
  • Subject: [mg61699] Re: [mg61647] Complex numbers in Mathematica
  • From: "Jose Luis Gomez" <jose.luis.gomez at itesm.mx>
  • Date: Wed, 26 Oct 2005 01:01:58 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

Hello!

I do get the correct complex number answer in my Mathematica 5.2

My guess is that somehow you loaded the RealOnly package in your Mathematica
session (Or maybe your Teacher's edition automatically loads this package? I
do Not know).

Here is the help about RealOnly:
http://documents.wolfram.com/mathematica/Add-onsLinks/StandardPackages/Misce
llaneous/RealOnly.html  

The package RealOnly was created in order to adapt Mathematica to students
that do not know about complex numbers. For example, students "know" that
the cubic root of -8 is -2. This is Not correct, the *main* cubic root of -8
is a complex number. Mathematica will give you the correct complex answer,
however if you load the package RealOnly, then Mathematica will change its
behavior and it will answer that the cubic root of -8 is -2. 

I hope that helps
Jose Luis
http://homepage.cem.itesm.mx/lgomez/

-----Mensaje original-----
De: "Per Rønne" [mailto:per at RQNNE.invalid] 
Enviado el: Lunes, 24 de Octubre de 2005 08:07 p.m.
Para: mathgroup at smc.vnet.net
Asunto: [mg61647] Complex numbers in Mathematica

If I write:

In[8]=Factor[(5 - 3I) + (-4 + I)x + (1 - I)x^2]

I get
Nonreal::"warning": "Nonreal number encountered."
Out[8]= Nonreal

The same with Sqrt[-1].

Why doesn't it show the complex numbers? According to the books it
should - is it a matter of preferences set?

I'm using Mathematica Teacher's Edition 1.1 on MacOS X.
-- 
Per Erik Rønne


  • Prev by Date: ParametricPlot3D
  • Next by Date: Re: Exporting XML as DocBook, etc
  • Previous by thread: Re: Complex numbers in Mathematica
  • Next by thread: notebook directory