Re: Absolute Value of Complex Numbers

*To*: mathgroup at smc.vnet.net*Subject*: [mg35201] Re: [mg35196] Absolute Value of Complex Numbers*From*: Andrzej Kozlowski <andrzej at tuins.ac.jp>*Date*: Tue, 2 Jul 2002 02:11:53 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

And how is Mathematica to know what k is? For example, it could be = I, which will give the answer 2/E and so on. Of course you meant k to be real but unfortunately Mathematica's mind reading technology is still in the development stage and won't be available before version 9.1. In the mean time you have to use: In[3]:= ComplexExpand[Abs[2 Exp[k*I]]] Out[3]= 2 or In[4]:= Simplify[Abs[2 Exp[k*I]],Element[k,Reals]] Out[4]= 2 which is really more than enough. Andrzej Kozlowski Toyama International University JAPAN http://platon.c.u-tokyo.ac.jp/andrzej/ On Monday, July 1, 2002, at 04:34 PM, Kyle Davis wrote: > 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? > > > >