From Euler's identity: i^i=exp(-pi/2)= 0.2079 (rounded)

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Discussion Overview

The discussion revolves around the expression \(i^i\) derived from Euler's identity, exploring its value and implications. Participants examine the multi-valued nature of the complex logarithm and the significance of the expression in mathematical contexts.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant states that \(i^i = \exp(-\pi/2) \approx 0.2079\) but questions its significance.
  • Another participant argues that \(i^i\) does not have a specific value, presenting it as \(i^i = e^{i^2(\frac{\pi}{2} + 2\pi n)}\) for all integers \(n\).
  • A participant reiterates the multi-valued nature of the complex logarithm, contrasting it with the real logarithm.
  • There is a discussion about the algebraic correctness of the expressions, with one participant noting that the \(+2\pi n\) term is not commonly seen in texts.
  • Participants suggest using LaTeX for clarity in mathematical expressions.

Areas of Agreement / Disagreement

Participants express differing views on the value of \(i^i\), with some asserting it has no specific value due to its multi-valued nature, while others present a specific numerical approximation. The discussion remains unresolved regarding the significance of the expression and the algebraic representations.

Contextual Notes

The discussion highlights the complexity of the multi-valued nature of the complex logarithm and its implications for expressions involving \(i^i\). There are unresolved aspects regarding the algebraic steps and the interpretation of the results.

SW VandeCarr
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From Euler's identity: i^i=exp(-pi/2)= 0.2079 (rounded). I've always thought of this as an interesting result although I don't know of any particular significance or consequence of it. Is there any?
 
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i^i does not have a specific value. [tex]i^i=e^{i^2(\frac{\pi}{2}+2\pi \cdot n) }=e^{-(\frac{\pi}{2}+2\pi \cdot n) }[/tex] for all integers n.
 
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Jarle said:
i^i does not have a specific value. [tex]i^2=e^{i^2(\frac{\pi}{2}+2\pi \cdot n) }=e^{-(\frac{\pi}{2}+2\pi \cdot n) }[/tex] for all integers n.

I'm using ^ as raising to a power except for 'exp' where exp(x) means e^x

exp(i pi)= -1

SQRT [exp(i pi) = SQRT (-1)

exp(i pi/2) = i

exp ((i^2) pi/2)) = i^i = exp (-pi/2) = 0.2079 (rounded)
 
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SW VandeCarr:

Jarle is also using it in that sense.

However, as he pointed out, the complex logarithm is a multi-valued mapping, in contrast to the real logarithm.
 


arildno said:
SW VandeCarr:

Jarle is also using it in that sense.

However, as he pointed out, the complex logarithm is a multi-valued mapping, in contrast to the real logarithm.

Thanks, but the algebra is correct, is it not? Normally I don't see the +2pi.n term in texts.
 
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Strange, I do!
 


SW VandeCarr - you can put "tex" tags around your equations and use latex syntax instead of defining all of your notation. It makes yours and everyone else's life easier :)
 


daviddoria said:
SW VandeCarr - you can put "tex" tags around your equations and use latex syntax instead of defining all of your notation. It makes yours and everyone else's life easier :)

Thanks daviddoria. I guess it's about time I started using latex if I'm going to be posting questions here.
 

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