Sequence based on sequential square root function

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Homework Help Overview

The discussion revolves around a sequence defined by a nested square root function, specifically \{\sqrt{2}, \sqrt{2\sqrt{2}}, \sqrt{2\sqrt{2\sqrt{2}}}, ...\}. Participants are exploring how to express each term as a power of 2 and are attempting to derive a formula for the sequence's limit.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants are examining the fractional exponents of the sequence and noting the absence of a common difference or ratio. They discuss recognizing patterns in the numerators and denominators, suggesting they increase by powers of two. There is also a focus on clarifying the expression of the exponent in the sequence.

Discussion Status

The discussion is active, with participants sharing insights and attempting to identify patterns in the sequence. Some guidance has been offered regarding the formulation of the exponent, but there is no explicit consensus on a final formula or limit.

Contextual Notes

Participants are working within the constraints of expressing terms as powers of 2 and are navigating the complexities of the sequence's structure without a complete formula. There is an emphasis on careful notation and clarity in mathematical expressions.

cscott
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Express each term of the sequence [tex]\{\sqrt{2}, \sqrt{2\sqrt{2}}, \sqrt{2\sqrt{2\sqrt{2}}}, ...\}[/tex] as a power of 2.

I found [itex]\{2^{\frac{1}{2}}, 2^{\frac{3}{4}}, 2^{\frac{7}{8}}, ...\}[/itex] but I can't get the formula for it so I can find it's limit.
 
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Try a few more then!

Or, it might be better just to write down a way to compute the next term from the current term.
 
If I consider just the fractional exponents as a sequence on its own, there is no common difference or common ratio so I'm stuck in this aspect.
 
Do you at least recognize the pattern?
 
The numerator and denominator go up by 2, 4, 8, 16, etc., or powers of two.
 
Last edited:
I see... so it'd be like [2^(n) - 1]/2^n ?
 
It seems to work for the first three!
 
cscott said:
I see... so it'd be like [2^(n) - 1]/2^n ?
Be careful with the parentheses. It should read:
2 ^ ((2 ^ (n) - 1) / 2 ^ n), or
[tex]2 ^ {\frac{2 ^ {n} - 1}{2 ^ n}}[/tex]
:)
 
Well, I thought he was writing down the formula for the exponent, not the term of his sequence!
 
  • #10
Hurkyl said:
Well, I thought he was writing down the formula for the exponent, not the term of his sequence!

Yeah, I meant it only as the exponent.
 

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