What Does The Logarithm of the Power of a Number Mean?

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Discussion Overview

The discussion revolves around the interpretation of logarithmic identities, particularly the rule that states "the logarithm of the power of a number is that power multiplied by the logarithm." Participants seek clarification on this concept and its implications in the context of logarithmic definitions and properties.

Discussion Character

  • Conceptual clarification
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant expresses confusion over the statement regarding logarithms and requests a breakdown of its meaning.
  • Another participant provides the mathematical expression \log (x^a) = a\log x to illustrate the rule in question.
  • Several participants discuss the definition of logarithms, specifically the relationship between exponentials and logarithms, as in the equation y = a^x leading to x = log_a(y).
  • There is a repeated inquiry about how x can equal log(x), with examples provided to clarify the relationship between exponents and logarithms.
  • One participant acknowledges a misunderstanding of a previous post and indicates a growing understanding of the topic.

Areas of Agreement / Disagreement

Participants generally express confusion about the logarithmic concepts being discussed, and there is no clear consensus on the understanding of the logarithmic identities. Multiple viewpoints and interpretations remain present throughout the discussion.

Contextual Notes

Some participants reference specific definitions and examples from their classes, indicating that understanding may depend on the context in which logarithms were taught. There are also indications of misinterpretations and clarifications that have not been fully resolved.

Euler
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I'm reading a book and there is a section about rules to do with logarithms but one of them I don't understand, it is very wordy and I just can't get what it means.

It says "The logarithm of the power of a number is that power multiplied by the logarithm." I really don't understand what that means, can anyone who does break it down for me?
 
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\log (x^a) = a\log x

The logarithm "log" of the power "a" of a number "x" on the LHS, the power "a" multiplied by the logarithm [of that number] "log a" on the RHS.
 
If y= a^x then x= log_a(y). That is often used as the definition of the logarithm. Exactly how was "log_a(x)" defined in your class?
 
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HallsofIvy said:
If y= a^x then x= log_a(y). That is often used as the definition of the logarithm. Exactly how was "log_a(x)" defined in your class?

How can x = the log of x? If we do 2^3 = 8 for example then log to the base 2 of 8 = 3, yes? I am still quite confused. I don't know why I can't understand this.
 
Euler said:
How can x = the log of x?

Who said ##x=\log(x)##?
Euler said:
If we do 2^3 = 8 for example then log to the base 2 of 8 = 3, yes? I am still quite confused. I don't know why I can't understand this.
yes. It is correct.
As HallsofIvy said before, if ##y=a^x## then ##\log_a(y)=x##.
I understand it this way: To what power should x be raised to get y?
 
adjacent said:
Who said ##x=\log(x)##?

yes. It is correct.
As HallsofIvy said before, if ##y=a^x## then ##\log_a(y)=x##.
I understand it this way: To what power should x be raised to get y?

I'm sorry, I misread HallsofIvy's post. I think I understand now.
 

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