Services & ResourcesWolfram ForumsMathGroup Archive

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

Re: Absolute Value of Complex Numbers

• To: mathgroup at smc.vnet.net
• Subject: [mg35210] Re: [mg35196] Absolute Value of Complex Numbers
• From: Tomas Garza <tgarza01 at prodigy.net.mx>
• Date: Tue, 2 Jul 2002 02:12:16 -0400 (EDT)
• References: <200207010734.DAA17391@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Mathematica is very conservative concerning properties of unknown objects.
Your k is a symbol about which nothing is known. Many of us would presume it
is an integer, but this has to be explicitly assumed. Then, for example,
using Assumptions in Simplify gives you the answer you were expecting:

 In[1]:=
Simplify[Abs[2*Exp[k*I]], k \[Element] Integers]
Out[1]=
2

Tomas Garza
Mexico City


----- Original Message -----
From: "Kyle Davis" <kyledavis at nowhere.com>
To: mathgroup at smc.vnet.net
Subject: [mg35210] [mg35196] Absolute Value of Complex Numbers


> Abs[2 Exp[3 * i]]
> answer = 2
>
> Abs[2 Exp[k * i]]
> answer = 2 Exp[-Im[k]]
>
> Isn't the second answer supposed to be the same with the first one,
> regardless with the value of k? How do I make the second calculation give
me
> the right answer?
>
>

• References:
  • Absolute Value of Complex Numbers
    • From: "Kyle Davis" <kyledavis@nowhere.com>