MHB Limits of Sequences .... Stoll Theorem 2.2.6

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The discussion centers on proving parts (a) and (b) of Theorem 2.2.6 from Manfred Stoll's "Introduction to Real Analysis," specifically regarding limits of special sequences. Participants express difficulty in starting the proof for part (a), despite Stoll's assertion that it is straightforward. A proposed solution involves demonstrating that the limit approaches zero using the epsilon-delta definition of limits. Confirmation from other users boosts confidence in the proposed approach, while questions arise about the foundational axioms or theorems used in the proof. The conversation highlights the collaborative effort to understand and prove mathematical concepts effectively.
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In his book: Introduction to Real Analysis, Manfred Stoll does not prove parts (a) and (b) of Theorem 2.2.6 on the limits to certain special sequences ...

I am having trouble getting started on the proof of part (a) ... can someone please help me to make a meaningful start to the proof ... (despite the fact that Stoll informs us that the proof is straightforward ... :( ... )

Theorem 2.2.6 reads as follows:

View attachment 7194Peter
 
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Peter said:
In his book: Introduction to Real Analysis, Manfred Stoll does not prove parts (a) and (b) of Theorem 2.2.6 on the limits to certain special sequences ...

I am having trouble getting started on the proof of part (a) ... can someone please help me to make a meaningful start to the proof ... (despite the fact that Stoll informs us that the proof is straightforward ... :( ... )

Theorem 2.2.6 reads as follows:

Peter

After some reflection I have a proposed solution ...To show $$\text{lim}_{ n \rightarrow \infty } = 0$$ Now ... for any $$\epsilon \gt 0$$ the inequality $$\left\lvert\frac{1}{ n^p } - 0\right\rvert \lt \epsilon$$gives $$\frac{1}{ n^p } \lt \epsilon$$ or $$n \gt \frac{1}{ \epsilon^{ \frac{1}{ p } }}$$ ... ... Hence ... if we take $$N \gt \frac{1}{ \epsilon^{ \frac{1}{ p } } } $$ ... then for $$n \gt N$$ we have ...$$\frac{1}{ n^p } \lt \left(\frac{1}{ \frac{1}{ \epsilon^{ \frac{1}{p} } } }\right)^p = \epsilon $$Is that correct?

Peter
 
Last edited:
Peter said:
After some reflection I have a proposed solution ...To show $$\text{lim}_{ n \rightarrow \infty } = 0$$ Now ... for any $$\epsilon \gt 0$$ the inequality $$\left\lvert\frac{1}{ n^p } - 0\right\rvert \lt \epsilon$$gives $$\frac{1}{ n^p } \lt \epsilon$$ or $$n \gt \frac{1}{ \epsilon^{ \frac{1}{ p } }}$$ ... ... Hence ... if we take $$N \gt \frac{1}{ \epsilon^{ \frac{1}{ p } } } $$ ... then for $$n \gt N$$ we have ...$$\frac{1}{ n^p } \lt \left(\frac{1}{ \frac{1}{ \epsilon^{ \frac{1}{p} } } }\right)^p = \epsilon $$Is that correct?

Peter
Yes! (Yes)
 
Opalg said:
Yes! (Yes)
Thanks Opalg ... it gives me great confidence when you or Evgeny confirm my effort ...

Thank you ...

Peter
 
Peter said:
After some reflection I have a proposed solution ...To show $$\text{lim}_{ n \rightarrow \infty } = 0$$ Now ... for any $$\epsilon \gt 0$$ the inequality $$\left\lvert\frac{1}{ n^p } - 0\right\rvert \lt \epsilon$$gives $$\frac{1}{ n^p } \lt \epsilon$$ or $$n \gt \frac{1}{ \epsilon^{ \frac{1}{ p } }}$$ ... ... Hence ... if we take $$N \gt \frac{1}{ \epsilon^{ \frac{1}{ p } } } $$ ... then for $$n \gt N$$ we have ...$$\frac{1}{ n^p } \lt \left(\frac{1}{ \frac{1}{ \epsilon^{ \frac{1}{p} } } }\right)^p = \epsilon $$Is that correct?

Peter

In going from: $$\frac{1}{ n^p } \lt \epsilon$$ to

$$n \gt \frac{1}{ \epsilon^{ \frac{1}{ p } }}$$

What are the axioms or theorems or definitions of the real Nos that you use??
 
We all know the definition of n-dimensional topological manifold uses open sets and homeomorphisms onto the image as open set in ##\mathbb R^n##. It should be possible to reformulate the definition of n-dimensional topological manifold using closed sets on the manifold's topology and on ##\mathbb R^n## ? I'm positive for this. Perhaps the definition of smooth manifold would be problematic, though.

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