Existence of Limit of [(x+iy)/(x-iy)]^n

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Homework Statement



For what values does the limit exist?
Lim_{n\rightarrow}\infty(\frac{z}{z conjugate})^n

Homework Equations





The Attempt at a Solution


[(x+iy)/(x-iy)]^n
I just don't know how to tell when it exists. For even values of n because then there would be no sign changes?
 
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It should be obvious that the existence or non-existence of the limit depends on z (alternatively, x and y) not on n, since n is the argument for the limit (aside: is there a name for that?)
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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