Taking a number to a complex number power

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Discussion Overview

The discussion revolves around computing powers of numbers, particularly focusing on complex exponents and non-integer powers. Participants explore the mathematical expressions and methods for evaluating these powers, including the use of logarithms and limits.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Conceptual clarification

Main Points Raised

  • One participant asks how to compute \(2^{it}\) where \(t\) is a real number, and also how to handle non-integer powers like \(2^{3.14}\).
  • Another participant provides a mathematical breakdown of \(2^{it}\) using the exponential function, stating \(2^{it} = \exp(it \log 2) = \cos(t \log 2) + i \sin(t \log 2)\).
  • It is proposed that \(2^{3.14}\) can be expressed as \( \exp(3.14 \log 2)\), although the participant expresses uncertainty about alternative representations.
  • A third participant notes that \(3.14\) is a rational number and provides a rational approximation for it, suggesting that \(2^{3.14}\) can be expressed as \(2^{157/50} = \sqrt[50]{2^{157}}\).
  • This participant also mentions that while \(\pi\) is irrational, there are rational sequences that converge to it, using \(2^{\pi}\) as an example of a limit of such sequences.
  • Another participant expresses gratitude for the responses and inquires about further resources regarding the sequence that converges to \(\pi\).

Areas of Agreement / Disagreement

Participants present various methods and interpretations for computing powers, with no clear consensus on a single approach or representation. The discussion includes both rational and irrational numbers, and the methods for handling them remain open to exploration.

Contextual Notes

Some assumptions about the properties of logarithms and the nature of convergence are present but not explicitly stated. The discussion does not resolve the complexities involved in calculating powers with complex exponents.

ucbugrad
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How do you compute the following?

2it where t is a real number

while I am at it, how do you compute powers that are not integers

ie: 23.14
 
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2^(it) = exp(it(log2)) = exp(i(tlog2)) = cos(tlog2) + isin(tlog2)

I guess we would define

2^(3.14) = exp(3.14(log2))

I'm not sure if i could write it in any other way, and i doubt i could compute that in my head but they are equivalent.

Sorry for the bad formatting if it isn't clear.

Edit: These logs are base e.
 
Last edited:
"3.14", as opposed to [itex]\pi[/itex], is a rational number. It is, in fact, [itex]314/100= 157/50[/itex] so [itex]2^{3.14}= 2^{157/50}= \sqrt[50]{2^{157}}[/itex].

[itex]\pi[/itex] is not rational but there exist a sequence of rational numbers that converge to it (the sequence 3, 3.1, 3.14, ..., for example). [itex]2^\pi[/itex] is equal to the limit of the sequence [itex]2^3[/itex], [itex]2^{3.1}= 2^{31/10}= \sqrt[10]{2^{31}}=[/itex], [itex]2^{3.14}= 2^{314/100}= \sqrt[50]{2^{157}}[/itex],...

Of course, to actually calculate those things you would use [itex]2^a= e^{a ln(2)}[/itex] as The1337gamer said.
 
Thank you all, both addressed all of my issues. Halls of Ivy: where can I find more about this sequence that converges to Pi? What is the formula for each term?
 

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