Finding the value of p so that the series converges

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SUMMARY

The discussion focuses on determining the values of p for which the series ∑1/(ln(n)*n^p) converges, starting from n=2. The integral test is employed, leading to the integral ∫dx/(ln(x)*x^p) from 2 to infinity. It is established that the series diverges for p ≤ 1, while for p > 1, a comparison test with 1/n^p confirms convergence. Thus, the series converges only when p > 1.

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  • Understanding of series convergence tests, specifically the integral test and comparison test.
  • Familiarity with logarithmic functions and their properties.
  • Basic knowledge of calculus, particularly integration techniques.
  • Concept of limits and their application in series and integrals.
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  • Study the integral test for convergence in more detail.
  • Learn about the comparison test and its applications in series convergence.
  • Explore advanced integration techniques, including substitution and limits at infinity.
  • Investigate other convergence tests such as the ratio test and root test.
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Mathematicians, calculus students, and anyone studying series convergence and integral calculus will benefit from this discussion.

Dell
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find the possible values of p so that the following converges

infinity
\sum1/(ln(n)*np)
n=2

what i thought of doing was integrating to find the values of p such that the integral will give me an answer not infinity.

\intdx/(ln(x)*xp) from 2-infnity

i thought of using substitution as
t=ln(x)
x=et
dt=dx/x

\intdt/(t*et(p-1)) from ln2-infinty


but i have no idea how to continue from here, i think that if p<=1 then my integral will diverge since lim(t->inf) will not be 0, but i am not sure, i know that with a series if lim(n->inf) is not 0 then the series diverges, is this true for integrals as well,
even so, if i know that p<=1 diverges, this does not automatically mean that anything else converges, since lim(n->inf)An=0 doesn't mean necessarily converges, how do i find the values for p where i KNOW the integral diverges??
 
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Your argument works for p <= 1.

To do arguments for p > 1, use a comparison test.. Show that each term (n>2) is less then
1/n^p.
 
so do i say:
for any n>2 my series is smaller than 1/n^p, and if p>1 1/n^p converge, therefore mine must also diverge, as for p<1 i already proved when i said lim(n->inf) not 0, so my series must diverge, therefore the series only converges when p>1,

do you see a better way of solving this?
 

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