If n=complex number what values of n in i^n real?

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Discussion Overview

The discussion centers on the values of a complex number \( n \) for which \( i^n \) is real. Participants explore theoretical implications, examples, and definitions related to complex numbers and their properties.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants suggest that there are an infinite number of real possibilities for \( i^n \) when \( n \) is complex, citing that \( 1+0i \) is still a complex number.
  • One participant provides an example where \( i^i \) is real, referencing the expression \( (it)^{it} = e^{-t\pi/2}[\cos(t\ln t) + i\sin(t\ln t)] \) being real for specific conditions on \( t \).
  • Another participant presents the equation \( i^n = \exp(n \log(i)) \) and discusses the conditions under which this expression is real, specifically mentioning the principal branch of the logarithm.
  • There is a repeated inquiry about whether \( i^n \) has an infinite number of real outcomes, with a participant asserting that they can prove \( i^i \) is real and that \( i^{ai} \) is also real under certain conditions.
  • Participants discuss the definition of complex numbers, confirming that \( a+0i \) is indeed a complex number, and that real numbers are a subset of complex numbers.

Areas of Agreement / Disagreement

Participants express differing views on the nature of \( i^n \) being real, with some asserting infinite possibilities while others focus on specific examples and conditions. The discussion remains unresolved regarding the extent of real values for \( i^n \) when \( n \) is complex.

Contextual Notes

Participants reference De Moivre's theorem and the principal branch of logarithms, indicating that the discussion may depend on specific mathematical definitions and interpretations that are not universally agreed upon.

brandy
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would in = an infinite amount of real possibilites if n is complex. considering that 1+0i is still a complex number, or is that wrong?
 
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For one example, ii is real. In fact,

[tex](it)^{it}=e^{-t\pi/2}[\cos(t\ln t) + i\sin(t\ln t)][/tex]

is real for t ln(t) = n pi, n integer.
 
i^n=exp(n log(i))
For the principle branch take log(i)=i*pi/2
i^n=exp(i*n*pi/2)
when will that be real?
 
i just asked if it would have an infinite amount of possibilites, obviously i have already thought about this and already know some examples of how it will be real. its a yes or no + justification response.

im using De Moirve's theorem and i can already prove that i^i is real. and hence i^ai is real even if its complex and if n=ai+c it will be real if c is an even number or o.

the other part of my question was, can i acurately say that a+0i is a complex number?
 
brandy said:
i just asked if it would have an infinite amount of possibilites, obviously i have already thought about this and already know some examples of how it will be real. its a yes or no + justification response.

im using De Moirve's theorem and i can already prove that i^i is real. and hence i^ai is real even if its complex and if n=ai+c it will be real if c is an even number or o.

the other part of my question was, can i acurately say that a+0i is a complex number?

Yes. The real numbers are a subset of the complex numbers.
 

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