Simplify Natural Logarithms: ln(i^2)^2 Explained | Sweet Bro"

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Discussion Overview

The discussion revolves around the simplification of the expression (ln(i^2))^2, particularly focusing on the implications of using logarithms with complex numbers. The scope includes mathematical reasoning and conceptual clarification regarding logarithmic properties in the context of complex analysis.

Discussion Character

  • Mathematical reasoning
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant notes that i^2 = -1 and suggests that ln(-1) can be expressed as ln[exp(i pi)] = i pi, leading to the simplification (i pi)^2 = -pi^2.
  • Another participant agrees that -pi^2 is a solution but questions the existence of other solutions, expressing confusion over the interpretation of "simplification."
  • A different participant points out that the principal branch of the logarithm is typically used when discussing the logarithm of a complex number, which relates to the principal value of the argument.
  • Concerns are raised about the multivalued nature of the logarithm, with a participant referencing their experience in complex analysis where ln denotes the multivalued version and Ln denotes the principal branch.

Areas of Agreement / Disagreement

Participants express differing views on whether -pi^2 is the only simplification or if other forms exist due to the multivalued nature of the logarithm. The discussion remains unresolved regarding the implications of using different branches of the logarithm.

Contextual Notes

There are limitations regarding the assumptions made about the logarithm's branch and the potential for multiple values when dealing with complex logarithms. The discussion does not resolve these aspects.

FUNKER
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what is the result or simplification of

( ln(i^2) )^2

sweet bro
:confused:
 
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Easy as pi

First, i^2=-1.

Then note that exp(i pi) = -1.

So ln(-1) = ln[exp(i pi)] = i pi.

Square it: (i pi)^2 = - pi^2.

EDIT: I should caution that this is a solution. I make no claim that it is the only solution.
 
Last edited:
[itex]-\pi^2[/itex] is definitely a solution. I'm not sure how there could be more solutions...?

- Warren
 
He wasn't even referring to solutions, was he? He just wanted a simplification of an expression, no?

cookiemonster
 
Well, heh, right, not solutions... I meant that [itex]-\pi^2[/itex] is the simplest possible form for it. I see what Janitor was saying now -- that there may be better simplifications. If so, I don't see any.

- Warren
 
Cookiemonster: he did ask, "What is the result..."

I'm not sure how there could be more solutions...?

Chroot, here's the sort of thing I am worried about:

Note that exp(3 i pi) = -1.

So ln(-1) = ln[exp(3 i pi)] = 3 i pi.

Square it: (3 i pi)^2 = - 9 pi^2.
 
the principal branch is usually what we mean when we ask for log of a complex number, which is the same as the principal value of arg, ie Arg
 
thanks for all ur help dudes, and yea I believe this is a solution as well as a simplification.
 
When I took complex analysis, we used ln for the multivalued version and Ln for the principal branch.
 

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