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

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The limit of [(x+iy)/(x-iy)]^n as n approaches infinity depends on the values of z, specifically x and y. For even values of n, the limit tends to exist due to the absence of sign changes in the expression. The discussion highlights that the existence of the limit is not influenced by n itself but rather by the characteristics of z. Understanding the behavior of the complex fraction is crucial for determining the limit's existence. Overall, the limit's existence is contingent on the specific values of x and y in the complex number z.
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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?)
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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