Misbehavior of Conjugate[Exp[I x]]
- To: mathgroup at yoda.physics.unc.edu
- Subject: Misbehavior of Conjugate[Exp[I x]]
- From: mek at guinan.psu.edu (Mark E. Kotanchek)
- Date: Tue, 2 Mar 93 16:42:07 -0500
Hi folks,
Right now I'm swearing at mma because taking the conjugate of a
complex exponential doesn't simplify much, i.e.,
In[35]:=
Conjugate[Exp[I x]]
Out[35]=
I x
Conjugate[E ]
Ok, you say this is because "x" could be complex; however, if I load
Algebra`ReIm` and define
In[36]:=
x /: Im[x] = 0
Out[36]=
0
I still get a result of
In[37]:=
Conjugate[Exp[I x]]
Out[37]=
I x
Conjugate[E ]
Now taking the Re[Exp[I x]] results in Cos[x] so mma at least
understands that x is now defined to be real. Is there something I
don't understand here or is this a deficiency in how mma handles (or
doesn't handle) complex-valued equations.
I'm also trying to do a series expansion of a complex-valued function
of theta about theta = 0, Arg[rho[theta]]] wherein mma gives me
answers involving the derivatives of "Arg". There may be subtleties
here; however, I suspect that a major source of the problem is that
mma is woefully deficient with respect to understanding domains. (Too
bad Derive isn't available for the NeXT!)
Any suggestions or comments?
Grumble, mutter, etc.,
Mark.
---
Mark Kotanchek
Guidance & Control Dept - 363 ASB
Applied Research Lab/Penn State
P.O. Box 30
State College, PA 16804
e-mail: mek at guinan.psu.edu (NeXTmail)
TEL: (814)863-0682
FAX: (814)863-7843