Help with a subtle point concerning the proof of the p-series test

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SUMMARY

The discussion focuses on proving the p-series test using the integral test, specifically addressing the behavior of the integral ∫(n)^(-p) dn as p approaches 1. It is established that for p > 1, the integral converges, while for p < 1, it diverges. The confusion arises around the limit as (-p + 1) approaches 0, but it is clarified that the p-series convergence theorem holds firm, indicating that p remains fixed and does not approach 1 in a way that affects convergence. The integral's behavior is definitively linked to the value of p.

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Homework Statement



Hi, I'm trying to prove the p-series test, using the integral test. Everything seems to work out fine until I get into this point:

Consider when p≠1 (p=1 is easy to see that it diverges, so I will ignore that one).

Then we have:

∫(n)^(-p) dn = [ 1 / (-p+1) ] * n^(-p+1)



For very large (-p+1) or very negatively large (-p+1), it is clear to see that the integral diverges and converges, respectively. But what if (-p+1) → 0? How do we know that the integral converges if p>1 and diverges if p<1? Shouldn't the limit approach 1 as anything to the zeroth power is equal to 1?
 
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In the p-series convergence theorem, p is fixed. If it is a bit different from 1, it will stay a bit different from 1. You need not worry about this.
 

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