RE: Absolute Value of Complex Numbers

*To*: mathgroup at smc.vnet.net*Subject*: [mg35207] RE: [mg35196] Absolute Value of Complex Numbers*From*: "David Park" <djmp at earthlink.net>*Date*: Tue, 2 Jul 2002 02:12:07 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Kyle, You are assuming that k is a real number, but Mathematica doesn't assume that. Use ComplexExpand to Simplify. (Perhaps they should have called it ComplexSimplify.) Abs[2 Exp[k*I]] // ComplexExpand 2 David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ > From: Kyle Davis [mailto:kyledavis at nowhere.com] To: mathgroup at smc.vnet.net > > 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? > >