How to Solve the Equation (x)^x^3=3?

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Discussion Overview

The discussion revolves around solving the equation \( (x)^{x^3} = 3 \). Participants explore various methods of approach, including analytical solutions, numerical methods, and calculus-based techniques. The conversation includes attempts to clarify the interpretation of the expression and its implications.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant suggests that the solution is the cubic root of 3, but does not provide a detailed justification.
  • Another participant argues that the equation cannot be solved analytically and proposes the use of numerical methods instead.
  • Some participants mention that the equation can be solved by inspection, noting specific transformations that lead to the conclusion.
  • There is a reference to a solution involving calculus, but details about the method are unclear, leading to requests for clarification.
  • Several participants discuss the non-associative nature of exponentiation and how it affects the interpretation of the expression \( x^{x^3} \).
  • Generalizations of the original problem are proposed, including forms like \( x^{x^n} = n \) and nested exponentials, with discussions on their validity and implications.
  • Participants express uncertainty about the correctness of their interpretations and calculations, leading to further questions and clarifications.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the method of solving the equation. Multiple competing views are presented, with some favoring analytical approaches and others advocating for numerical methods. The interpretation of the equation and the implications of exponentiation also remain contested.

Contextual Notes

There are limitations regarding the assumptions made about the expression \( x^{x^3} \), particularly concerning the placement of parentheses and the evaluation order in exponentiation. Some mathematical steps and interpretations remain unresolved.

  • #31
D H said:
No. I meant to write

\left (\sqrt 2 ^{\sqrt 2}\right)^{\sqrt 2} = 2

\left( \left(\sqrt[3]3 ^{\sqrt[3]3}\right)^{\sqrt[3]3}\right)^{\sqrt[3]3} = 3

I left out the parentheses, which are absolutely essential as exponentiation is non-associative.

No, you put them in but apparently in the wrong spot.
 
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  • #32
\log_n\Biggl(\underbrace{\sqrt[n] n^{\left(\sqrt[n] n^{\left(\dotsm^{\sqrt[n] n}}\right)}\right)}_{n+1}\Biggr) =

probbably he meant to write it sth like this:

\log_n (...(((\sqrt[n]^n)^{\sqrt [n]^n})^{\sqrt [n]^n})^{\sqrt [n]^n}...)^{\sqrt [n]^n} =\sqrt[n]^n \log_n (...(((\sqrt[n]^n)^{\sqrt [n]^n})^{\sqrt [n]^n})^{\sqrt [n]^n}...)=\sqrt [n]^n^{2} \log_n(..((\sqrt[n]^n)^{\sqrt[n]^n})^{\sqrt[n]^n})..)..=...=\sqrt[n]^n^{n}log_n\sqrt[n]^n=n*\frac{1}{n}log_n n=1 and hence:



(...(((\sqrt[n]^n)^{\sqrt [n]^n})^{\sqrt [n]^n})^{\sqrt [n]^n}...)^{\sqrt [n]^n}=n

Does this make any sense??
 
Last edited:
  • #33
sutupidmath said:
\log_n\Biggl(\underbrace{\sqrt[n] n^{\left(\sqrt[n] n^{\left(\dotsm^{\sqrt[n] n}}\right)}\right)}_{n+1}\Biggr) =

probbably he meant to write it sth like this:

\log_n (...(((\sqrt[n]^n)^{\sqrt [n]^n})^{\sqrt [n]^n})^{\sqrt [n]^n}...)^{\sqrt [n]^n} =\sqrt[n]^n \log_n (...(((\sqrt[n]^n)^{\sqrt [n]^n})^{\sqrt [n]^n})^{\sqrt [n]^n}...)=\sqrt [n]^n^{2} \log_n(..((\sqrt[n]^n)^{\sqrt[n]^n})^{\sqrt[n]^n})..)..=...=\sqrt[n]^n^{n}log_n\sqrt[n]^n=n*\frac{1}{n}log_n n=1 and hence:



(...(((\sqrt[n]^n)^{\sqrt [n]^n})^{\sqrt [n]^n})^{\sqrt [n]^n}...)^{\sqrt [n]^n}=n

Does this make any sense??

You don't even need logs to show that sense

(x^a)^b=x^(ab)
 

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