What's the convergence radius for $sumlimits_{n=1}^{infty}a_n(2x-1)^n$?
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Question
$sumlimits_{n=1}^{infty}a_n(2x-1)^n$ is convergent at $x=-2$, and divergent at $x=3$. Find its convergence radius $R$.
My result is $R=dfrac{5}{2}$, but some one else said $R=5$. Which is right?
power-series
asked Dec 14 '18 at 15:28
mengdie1982mengdie1982
4,927618
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add a comment |
$begingroup$
Question
$sumlimits_{n=1}^{infty}a_n(2x-1)^n$ is convergent at $x=-2$, and divergent at $x=3$. Find its convergence radius $R$.
My result is $R=dfrac{5}{2}$, but some one else said $R=5$. Which is right?
power-series
asked Dec 14 '18 at 15:28
mengdie1982mengdie1982
4,927618
$endgroup$
1
$begingroup$
I agree, $5/2$. But in this forum, you should show your work before expecting an answer.
$endgroup$
– GEdgar
Dec 14 '18 at 15:35
add a comment |
$begingroup$
Question
$sumlimits_{n=1}^{infty}a_n(2x-1)^n$ is convergent at $x=-2$, and divergent at $x=3$. Find its convergence radius $R$.
My result is $R=dfrac{5}{2}$, but some one else said $R=5$. Which is right?
power-series
asked Dec 14 '18 at 15:28
mengdie1982mengdie1982
4,927618
$endgroup$
Question
$sumlimits_{n=1}^{infty}a_n(2x-1)^n$ is convergent at $x=-2$, and divergent at $x=3$. Find its convergence radius $R$.
My result is $R=dfrac{5}{2}$, but some one else said $R=5$. Which is right?
power-series
power-series
asked Dec 14 '18 at 15:28
mengdie1982mengdie1982
4,927618
asked Dec 14 '18 at 15:28
mengdie1982mengdie1982
4,927618
asked Dec 14 '18 at 15:28
mengdie1982mengdie1982
4,927618
asked Dec 14 '18 at 15:28
mengdie1982mengdie1982
4,927618
asked Dec 14 '18 at 15:28
mengdie1982mengdie1982
4,927618
4,927618
1
$begingroup$
I agree, $5/2$. But in this forum, you should show your work before expecting an answer.
$endgroup$
– GEdgar
Dec 14 '18 at 15:35
add a comment |
1
$begingroup$
I agree, $5/2$. But in this forum, you should show your work before expecting an answer.
$endgroup$
– GEdgar
Dec 14 '18 at 15:35
1
1
$begingroup$
I agree, $5/2$. But in this forum, you should show your work before expecting an answer.
$endgroup$
– GEdgar
Dec 14 '18 at 15:35
$begingroup$
I agree, $5/2$. But in this forum, you should show your work before expecting an answer.
$endgroup$
– GEdgar
Dec 14 '18 at 15:35
add a comment |
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I agree, $5/2$. But in this forum, you should show your work before expecting an answer.
$endgroup$
– GEdgar
Dec 14 '18 at 15:35