Proving Convergence: Real s, 0<s<1, n \to \infty

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SUMMARY

The discussion focuses on proving that the expression ns - (n-1)s converges to zero as n approaches infinity for real numbers s where 0 < s < 1. The participants suggest using the Mean Value Theorem to derive the limit, leading to the conclusion that s(n + ξ)s-1 approaches zero. This method provides an elementary proof without requiring advanced calculus or infinite binomial expansion.

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  • Understanding of the Mean Value Theorem
  • Basic knowledge of limits in calculus
  • Familiarity with real number properties
  • Elementary calculus concepts
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Students of calculus, mathematics educators, and anyone interested in elementary proofs of convergence in real analysis.

disregardthat
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How can we prove that [tex]n^s-(n-1)^s[/tex] converge to zero as [tex]n \to \infty[/tex] where s as a real number satisfies [tex]0<s<1[/tex]?

I am specifically looking for a more or less elementary proof for this for real s. I think we can use the infinite binomial expansion, but I am looking for something that does not require more than elementary calculus.
 
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I thought about the graph of that function and why the limit is "obvious" from the graph. Translating the graph picture into mathematics, I think an easy way is the mean value theorem.
With it you find
[tex] n^s-(n-1)^s=s(n+\xi)^{s-1}\to 0[/tex]
 
Gerenuk said:
I thought about the graph of that function and why the limit is "obvious" from the graph. Translating the graph picture into mathematics, I think an easy way is the mean value theorem.
With it you find
[tex] n^s-(n-1)^s=s(n+\xi)^{s-1}\to 0[/tex]

Excellent, nice and easy proof!
 

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