From: Daniel Carrera <dcarrera@...>
Date: 2003-02-06T06:24:04+09:00
Subject: Error in Complex

Hello,

There seems to be a problem in Complex.  It gets (-i)^2/3 wrong.

 2/3
i    =  1/2 + sqrt(3)/2

   2/3
(-i) = - 1


With Ruby:
$ irb
>> require 'complex'
=> true
>> Complex(0,1)**(2.0/3)    #  i^2/3 
=> Complex(0.5000000000000001, 0.8660254037844386)
>> Complex(0,-1)**(2.0/3)    #  (-i)^2/3
=> Complex(0.5000000000000001, -0.8660254037844386)


The weird thing is that Maple gets this wrong too.
I tried to use Mathematica, but I just can't get the darn thing to work.  
So I don't know what Mathematica gets.

Does anyone know what's going on?

-- 
Daniel Carrera
Graduate Teaching Assistant.  Math Dept.
University of Maryland.  (301) 405-5137