Re: Complex Variables

*To*: mathgroup at smc.vnet.net*Subject*: [mg55430] Re: Complex Variables*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Wed, 23 Mar 2005 05:34:40 -0500 (EST)*Organization*: Mathematics & Statistics, Univ. of Mass./Amherst*References*: <200503220851.DAA23753@smc.vnet.net>*Reply-to*: murray at math.umass.edu*Sender*: owner-wri-mathgroup at wolfram.com

How is Mathematica supposed to know that you intend x and y to be real?? In such situations, ComplexExpand is usually your friend: ComplexExpand[Re[x + I y]] ComplexExpand[Im[x + I y]] ComplexExpand[Conjugate[x + I y]] give results x, y, and x - I y, respectively. And don't forget to use either I or else, for Mathematica's special symbol for the complex number, Esc ii Esc (or the equivalent\[Imaginary] or Esc jj Esc or \[ImaginaryJ]). wwolfe18 at comcast.net wrote: > This has been annoying me for a while. > Is there a way to declare symbols to be real so that > Re[x + i y] gives x and Conjugate[x + i y] gives x - i y etc? -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305

**References**:**Complex Variables***From:*<wwolfe18@comcast.net>