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

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The discussion focuses on proving that n^s - (n-1)^s converges to zero as n approaches infinity for real s in the range 0 < s < 1. An elementary proof is sought, ideally using basic calculus concepts without advanced techniques. The mean value theorem is suggested as a method to demonstrate this convergence, leading to the expression s(n + ξ)^(s-1), which approaches zero. The graph of the function also provides an intuitive understanding of the limit. The proposed approach is recognized as an effective and straightforward proof.
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How can we prove that n^s-(n-1)^s converge to zero as n \to \infty where s as a real number satisfies 0&lt;s&lt;1?

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
<br /> n^s-(n-1)^s=s(n+\xi)^{s-1}\to 0<br />
 
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
<br /> n^s-(n-1)^s=s(n+\xi)^{s-1}\to 0<br />

Excellent, nice and easy proof!
 
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