How to prove the convergence of the following series The Next CEO of Stack OverflowConvergence of alternating series not subject to alternating series testSeries and uniform convergenceProve series convergenceBig O and little o, absolute convergence of series where $a_n = O(b_n) $ or $a_n = o(b_n)$Convergence of a sum of seriesProve if $sumlimits_n=1^ infty a_n$ converges, $b_n$ is bounded & monotone, then $sumlimits_n=1^ infty a_nb_n$ converges.A question about real series $sum_n=1^infty a_n$ and $sum_n=1^infty b_n$Proof of convergence of sequences and Fourier series convergenceConvergence of series $sum_n=1^infty frac1+x^2nn^6$Help with convergence tests for series
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How to prove the convergence of the following series
The Next CEO of Stack OverflowConvergence of alternating series not subject to alternating series testSeries and uniform convergenceProve series convergenceBig O and little o, absolute convergence of series where $a_n = O(b_n) $ or $a_n = o(b_n)$Convergence of a sum of seriesProve if $sumlimits_n=1^ infty a_n$ converges, $b_n$ is bounded & monotone, then $sumlimits_n=1^ infty a_nb_n$ converges.A question about real series $sum_n=1^infty a_n$ and $sum_n=1^infty b_n$Proof of convergence of sequences and Fourier series convergenceConvergence of series $sum_n=1^infty frac1+x^2nn^6$Help with convergence tests for series
$begingroup$
Show that if $a_n,b_ninmathbbR$, $(a_n+b_n)b_nneq0$ and both $displaystylesum_n=1^inftyfraca_nb_n$ and $displaystylesum_n=1^inftyleft(fraca_nb_nright)^2$ converge, then $displaystylesum_n=1^inftyfraca_na_n+b_n$ converges.
If $a_n$ is positive, I have been able to solve. How we can solve in general?
real-analysis sequences-and-series
$endgroup$
add a comment |
$begingroup$
Show that if $a_n,b_ninmathbbR$, $(a_n+b_n)b_nneq0$ and both $displaystylesum_n=1^inftyfraca_nb_n$ and $displaystylesum_n=1^inftyleft(fraca_nb_nright)^2$ converge, then $displaystylesum_n=1^inftyfraca_na_n+b_n$ converges.
If $a_n$ is positive, I have been able to solve. How we can solve in general?
real-analysis sequences-and-series
$endgroup$
add a comment |
$begingroup$
Show that if $a_n,b_ninmathbbR$, $(a_n+b_n)b_nneq0$ and both $displaystylesum_n=1^inftyfraca_nb_n$ and $displaystylesum_n=1^inftyleft(fraca_nb_nright)^2$ converge, then $displaystylesum_n=1^inftyfraca_na_n+b_n$ converges.
If $a_n$ is positive, I have been able to solve. How we can solve in general?
real-analysis sequences-and-series
$endgroup$
Show that if $a_n,b_ninmathbbR$, $(a_n+b_n)b_nneq0$ and both $displaystylesum_n=1^inftyfraca_nb_n$ and $displaystylesum_n=1^inftyleft(fraca_nb_nright)^2$ converge, then $displaystylesum_n=1^inftyfraca_na_n+b_n$ converges.
If $a_n$ is positive, I have been able to solve. How we can solve in general?
real-analysis sequences-and-series
real-analysis sequences-and-series
asked 1 hour ago
J.DoeJ.Doe
542
542
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1 Answer
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$begingroup$
Write $c_n=fraca_nb_n$. Then we have $c_nne -1$, and also $sum c_n$, $sum c_n^2$ converge. We need to show $sum fracc_n1+c_n$ converges.
It suffices to show that the sum of
$$c_n-fracc_n1+c_n=fracc_n^21+c_n.$$
converges, since $sum c_n$ converges.
But $1+c_nto 1$. Then $sumfracc_n^21+c_n$ converges by comparison to $sum c_n^2 $.
$endgroup$
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1 Answer
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$begingroup$
Write $c_n=fraca_nb_n$. Then we have $c_nne -1$, and also $sum c_n$, $sum c_n^2$ converge. We need to show $sum fracc_n1+c_n$ converges.
It suffices to show that the sum of
$$c_n-fracc_n1+c_n=fracc_n^21+c_n.$$
converges, since $sum c_n$ converges.
But $1+c_nto 1$. Then $sumfracc_n^21+c_n$ converges by comparison to $sum c_n^2 $.
$endgroup$
add a comment |
$begingroup$
Write $c_n=fraca_nb_n$. Then we have $c_nne -1$, and also $sum c_n$, $sum c_n^2$ converge. We need to show $sum fracc_n1+c_n$ converges.
It suffices to show that the sum of
$$c_n-fracc_n1+c_n=fracc_n^21+c_n.$$
converges, since $sum c_n$ converges.
But $1+c_nto 1$. Then $sumfracc_n^21+c_n$ converges by comparison to $sum c_n^2 $.
$endgroup$
add a comment |
$begingroup$
Write $c_n=fraca_nb_n$. Then we have $c_nne -1$, and also $sum c_n$, $sum c_n^2$ converge. We need to show $sum fracc_n1+c_n$ converges.
It suffices to show that the sum of
$$c_n-fracc_n1+c_n=fracc_n^21+c_n.$$
converges, since $sum c_n$ converges.
But $1+c_nto 1$. Then $sumfracc_n^21+c_n$ converges by comparison to $sum c_n^2 $.
$endgroup$
Write $c_n=fraca_nb_n$. Then we have $c_nne -1$, and also $sum c_n$, $sum c_n^2$ converge. We need to show $sum fracc_n1+c_n$ converges.
It suffices to show that the sum of
$$c_n-fracc_n1+c_n=fracc_n^21+c_n.$$
converges, since $sum c_n$ converges.
But $1+c_nto 1$. Then $sumfracc_n^21+c_n$ converges by comparison to $sum c_n^2 $.
answered 1 hour ago
Eclipse SunEclipse Sun
7,9451438
7,9451438
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