Why $ lim_nrightarrow infty fracn!n^k(n-k)! =1 $? Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)Why does $lim_ntoinfty fracn!(n-k)!n^k$ equal 1Limits involving factorials $lim_Ntoinfty fracN!(N-k)!N^k$Finding limit of sequence: $lim _n to infty fracn!n^k(n-k)!=1$Proof that $limlimits_h to infty frach!h^k(h-k)!=1 $ for any $ k $Evaluating $lim_nrightarrowinftyleft(1-fracxn^1+aright)^n$Computing $lim_nrightarrowinfty(1-fracxn)^-n$Dominated convergence theorem for complex-valued functions?Limit to Expectation: $ - lim_N rightarrow infty frac1N sum_n=1^N fracpartialpartial theta ln p(x_n|theta)$Evaluation of $lim_mtoinftyBig(F(e^-fraclambdam^2)Big)^m$ given $F(z)=frac1-sqrt1-z^2z$Compute $lim_nrightarrowinftyleft(fracn+1nright)^n^2cdotfrac1e^n.$Find $lim_nrightarrow inftyfrac(2n-1)!!(2n)!!.$Finding $limsup_nrightarrowinfty n^fraclog(n)n$How to prove $lim_n rightarrowinfty e^-nsum_k=0^nfracn^kk! = frac12$?Show: $lim_nrightarrow infty left|int_1^eleft[ln(x)right]^n:dx right|= 0 $

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Why $ lim_nrightarrow infty fracn!n^k(n-k)! =1 $?



Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)Why does $lim_ntoinfty fracn!(n-k)!n^k$ equal 1Limits involving factorials $lim_Ntoinfty fracN!(N-k)!N^k$Finding limit of sequence: $lim _n to infty fracn!n^k(n-k)!=1$Proof that $limlimits_h to infty frach!h^k(h-k)!=1 $ for any $ k $Evaluating $lim_nrightarrowinftyleft(1-fracxn^1+aright)^n$Computing $lim_nrightarrowinfty(1-fracxn)^-n$Dominated convergence theorem for complex-valued functions?Limit to Expectation: $ - lim_N rightarrow infty frac1N sum_n=1^N fracpartialpartial theta ln p(x_n|theta)$Evaluation of $lim_mtoinftyBig(F(e^-fraclambdam^2)Big)^m$ given $F(z)=frac1-sqrt1-z^2z$Compute $lim_nrightarrowinftyleft(fracn+1nright)^n^2cdotfrac1e^n.$Find $lim_nrightarrow inftyfrac(2n-1)!!(2n)!!}.$Finding $limsup_nrightarrowinfty n^{fraclog(n)n$How to prove $lim_n rightarrowinfty e^-nsum_k=0^nfracn^kk! = frac12$?Show: $lim_nrightarrow infty left|int_1^eleft[ln(x)right]^n:dx right|= 0 $










2












$begingroup$


I was on brilliant.org learning probability. There was a process explaining how the distribution of a Poisson Random Variable can be obtained from a Binomial Random Variable.



Consider the binomial distribution:



$$
beginequationbeginaligned
P(X=k) &=binom n k p^k (1-p)^n-k\
&=fracn!k!(n-k)! p^k (1-p)^n-k
endalignedendequation
$$


Substitute $m=np$ , or $p=fracmn$ :
$$
beginequationbeginaligned
P(X=k) &=fracn!k!(n-k)! left(fracmnright)^k left(1-fracmnright)^n-k\
&=fracn!k!(n-k)! fracm^kn^k left(1-fracmnright)^nleft(1-fracmnright)^-k
endalignedendequation
$$


Slightly rearrange
$$
beginequationbeginaligned
&=fracn!n^k(n-k)! left(1-fracmnright)^-kfracm^kk!left(1-fracmnright)^n
endalignedendequation
$$




Note that
$$
beginequationbeginaligned
& lim_nrightarrow infty fracn!n^k(n-k)! =1,quadlim_nrightarrow infty left(1-fracmnright)^-k =1,quad lim_nrightarrow infty left(1-fracmnright)^n =e^-m
endalignedendequation
$$




Thus, we have the final result which is equal to the formula for the Poisson distribution.



$$
=fracm^k e^-mk!
$$




In all these steps, what I don't understand is the following limit:
$$
lim_nrightarrow infty fracn!n^k(n-k)! =1
$$











share|cite|improve this question











$endgroup$











  • $begingroup$
    There are several posts about this: Why does $lim_ntoinfty fracn!(n-k)!n^k$ equal 1, Finding limit of sequence: $lim _n to infty fracn!n^k(n-k)!=1$, Proof that $limlimits_h to infty frach!h^k(h-k)!=1$ for any $k$, Limits involing Factorials $lim_Ntoinfty fracN!(N-k)!N^k$
    $endgroup$
    – Martin Sleziak
    yesterday











  • $begingroup$
    I found the posts in the above comment using Approach0. For some useful tips on searching here see: How to search on this site?
    $endgroup$
    – Martin Sleziak
    yesterday










  • $begingroup$
    Some of the other posts treating the same question painfully lack details and context. Maybe you'd want to put them on hold or close them.
    $endgroup$
    – billyandr
    yesterday











  • $begingroup$
    billyandr: If you actually have a look at those links, you can see that two of those posts are closed (as duplicates) now. Let me also say that the fact that you have added some more context to your question is certainly appreciated. (After all, that's what lead to reopening.)
    $endgroup$
    – Martin Sleziak
    yesterday















2












$begingroup$


I was on brilliant.org learning probability. There was a process explaining how the distribution of a Poisson Random Variable can be obtained from a Binomial Random Variable.



Consider the binomial distribution:



$$
beginequationbeginaligned
P(X=k) &=binom n k p^k (1-p)^n-k\
&=fracn!k!(n-k)! p^k (1-p)^n-k
endalignedendequation
$$


Substitute $m=np$ , or $p=fracmn$ :
$$
beginequationbeginaligned
P(X=k) &=fracn!k!(n-k)! left(fracmnright)^k left(1-fracmnright)^n-k\
&=fracn!k!(n-k)! fracm^kn^k left(1-fracmnright)^nleft(1-fracmnright)^-k
endalignedendequation
$$


Slightly rearrange
$$
beginequationbeginaligned
&=fracn!n^k(n-k)! left(1-fracmnright)^-kfracm^kk!left(1-fracmnright)^n
endalignedendequation
$$




Note that
$$
beginequationbeginaligned
& lim_nrightarrow infty fracn!n^k(n-k)! =1,quadlim_nrightarrow infty left(1-fracmnright)^-k =1,quad lim_nrightarrow infty left(1-fracmnright)^n =e^-m
endalignedendequation
$$




Thus, we have the final result which is equal to the formula for the Poisson distribution.



$$
=fracm^k e^-mk!
$$




In all these steps, what I don't understand is the following limit:
$$
lim_nrightarrow infty fracn!n^k(n-k)! =1
$$











share|cite|improve this question











$endgroup$











  • $begingroup$
    There are several posts about this: Why does $lim_ntoinfty fracn!(n-k)!n^k$ equal 1, Finding limit of sequence: $lim _n to infty fracn!n^k(n-k)!=1$, Proof that $limlimits_h to infty frach!h^k(h-k)!=1$ for any $k$, Limits involing Factorials $lim_Ntoinfty fracN!(N-k)!N^k$
    $endgroup$
    – Martin Sleziak
    yesterday











  • $begingroup$
    I found the posts in the above comment using Approach0. For some useful tips on searching here see: How to search on this site?
    $endgroup$
    – Martin Sleziak
    yesterday










  • $begingroup$
    Some of the other posts treating the same question painfully lack details and context. Maybe you'd want to put them on hold or close them.
    $endgroup$
    – billyandr
    yesterday











  • $begingroup$
    billyandr: If you actually have a look at those links, you can see that two of those posts are closed (as duplicates) now. Let me also say that the fact that you have added some more context to your question is certainly appreciated. (After all, that's what lead to reopening.)
    $endgroup$
    – Martin Sleziak
    yesterday













2












2








2


1



$begingroup$


I was on brilliant.org learning probability. There was a process explaining how the distribution of a Poisson Random Variable can be obtained from a Binomial Random Variable.



Consider the binomial distribution:



$$
beginequationbeginaligned
P(X=k) &=binom n k p^k (1-p)^n-k\
&=fracn!k!(n-k)! p^k (1-p)^n-k
endalignedendequation
$$


Substitute $m=np$ , or $p=fracmn$ :
$$
beginequationbeginaligned
P(X=k) &=fracn!k!(n-k)! left(fracmnright)^k left(1-fracmnright)^n-k\
&=fracn!k!(n-k)! fracm^kn^k left(1-fracmnright)^nleft(1-fracmnright)^-k
endalignedendequation
$$


Slightly rearrange
$$
beginequationbeginaligned
&=fracn!n^k(n-k)! left(1-fracmnright)^-kfracm^kk!left(1-fracmnright)^n
endalignedendequation
$$




Note that
$$
beginequationbeginaligned
& lim_nrightarrow infty fracn!n^k(n-k)! =1,quadlim_nrightarrow infty left(1-fracmnright)^-k =1,quad lim_nrightarrow infty left(1-fracmnright)^n =e^-m
endalignedendequation
$$




Thus, we have the final result which is equal to the formula for the Poisson distribution.



$$
=fracm^k e^-mk!
$$




In all these steps, what I don't understand is the following limit:
$$
lim_nrightarrow infty fracn!n^k(n-k)! =1
$$











share|cite|improve this question











$endgroup$




I was on brilliant.org learning probability. There was a process explaining how the distribution of a Poisson Random Variable can be obtained from a Binomial Random Variable.



Consider the binomial distribution:



$$
beginequationbeginaligned
P(X=k) &=binom n k p^k (1-p)^n-k\
&=fracn!k!(n-k)! p^k (1-p)^n-k
endalignedendequation
$$


Substitute $m=np$ , or $p=fracmn$ :
$$
beginequationbeginaligned
P(X=k) &=fracn!k!(n-k)! left(fracmnright)^k left(1-fracmnright)^n-k\
&=fracn!k!(n-k)! fracm^kn^k left(1-fracmnright)^nleft(1-fracmnright)^-k
endalignedendequation
$$


Slightly rearrange
$$
beginequationbeginaligned
&=fracn!n^k(n-k)! left(1-fracmnright)^-kfracm^kk!left(1-fracmnright)^n
endalignedendequation
$$




Note that
$$
beginequationbeginaligned
& lim_nrightarrow infty fracn!n^k(n-k)! =1,quadlim_nrightarrow infty left(1-fracmnright)^-k =1,quad lim_nrightarrow infty left(1-fracmnright)^n =e^-m
endalignedendequation
$$




Thus, we have the final result which is equal to the formula for the Poisson distribution.



$$
=fracm^k e^-mk!
$$




In all these steps, what I don't understand is the following limit:
$$
lim_nrightarrow infty fracn!n^k(n-k)! =1
$$








limits factorial






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited yesterday







billyandr

















asked 2 days ago









billyandrbillyandr

237




237











  • $begingroup$
    There are several posts about this: Why does $lim_ntoinfty fracn!(n-k)!n^k$ equal 1, Finding limit of sequence: $lim _n to infty fracn!n^k(n-k)!=1$, Proof that $limlimits_h to infty frach!h^k(h-k)!=1$ for any $k$, Limits involing Factorials $lim_Ntoinfty fracN!(N-k)!N^k$
    $endgroup$
    – Martin Sleziak
    yesterday











  • $begingroup$
    I found the posts in the above comment using Approach0. For some useful tips on searching here see: How to search on this site?
    $endgroup$
    – Martin Sleziak
    yesterday










  • $begingroup$
    Some of the other posts treating the same question painfully lack details and context. Maybe you'd want to put them on hold or close them.
    $endgroup$
    – billyandr
    yesterday











  • $begingroup$
    billyandr: If you actually have a look at those links, you can see that two of those posts are closed (as duplicates) now. Let me also say that the fact that you have added some more context to your question is certainly appreciated. (After all, that's what lead to reopening.)
    $endgroup$
    – Martin Sleziak
    yesterday
















  • $begingroup$
    There are several posts about this: Why does $lim_ntoinfty fracn!(n-k)!n^k$ equal 1, Finding limit of sequence: $lim _n to infty fracn!n^k(n-k)!=1$, Proof that $limlimits_h to infty frach!h^k(h-k)!=1$ for any $k$, Limits involing Factorials $lim_Ntoinfty fracN!(N-k)!N^k$
    $endgroup$
    – Martin Sleziak
    yesterday











  • $begingroup$
    I found the posts in the above comment using Approach0. For some useful tips on searching here see: How to search on this site?
    $endgroup$
    – Martin Sleziak
    yesterday










  • $begingroup$
    Some of the other posts treating the same question painfully lack details and context. Maybe you'd want to put them on hold or close them.
    $endgroup$
    – billyandr
    yesterday











  • $begingroup$
    billyandr: If you actually have a look at those links, you can see that two of those posts are closed (as duplicates) now. Let me also say that the fact that you have added some more context to your question is certainly appreciated. (After all, that's what lead to reopening.)
    $endgroup$
    – Martin Sleziak
    yesterday















$begingroup$
There are several posts about this: Why does $lim_ntoinfty fracn!(n-k)!n^k$ equal 1, Finding limit of sequence: $lim _n to infty fracn!n^k(n-k)!=1$, Proof that $limlimits_h to infty frach!h^k(h-k)!=1$ for any $k$, Limits involing Factorials $lim_Ntoinfty fracN!(N-k)!N^k$
$endgroup$
– Martin Sleziak
yesterday





$begingroup$
There are several posts about this: Why does $lim_ntoinfty fracn!(n-k)!n^k$ equal 1, Finding limit of sequence: $lim _n to infty fracn!n^k(n-k)!=1$, Proof that $limlimits_h to infty frach!h^k(h-k)!=1$ for any $k$, Limits involing Factorials $lim_Ntoinfty fracN!(N-k)!N^k$
$endgroup$
– Martin Sleziak
yesterday













$begingroup$
I found the posts in the above comment using Approach0. For some useful tips on searching here see: How to search on this site?
$endgroup$
– Martin Sleziak
yesterday




$begingroup$
I found the posts in the above comment using Approach0. For some useful tips on searching here see: How to search on this site?
$endgroup$
– Martin Sleziak
yesterday












$begingroup$
Some of the other posts treating the same question painfully lack details and context. Maybe you'd want to put them on hold or close them.
$endgroup$
– billyandr
yesterday





$begingroup$
Some of the other posts treating the same question painfully lack details and context. Maybe you'd want to put them on hold or close them.
$endgroup$
– billyandr
yesterday













$begingroup$
billyandr: If you actually have a look at those links, you can see that two of those posts are closed (as duplicates) now. Let me also say that the fact that you have added some more context to your question is certainly appreciated. (After all, that's what lead to reopening.)
$endgroup$
– Martin Sleziak
yesterday




$begingroup$
billyandr: If you actually have a look at those links, you can see that two of those posts are closed (as duplicates) now. Let me also say that the fact that you have added some more context to your question is certainly appreciated. (After all, that's what lead to reopening.)
$endgroup$
– Martin Sleziak
yesterday










2 Answers
2






active

oldest

votes


















6












$begingroup$

It is rather obvious if you cancel the factorials:



$$fracn!n^k(n-k)! =fracoverbracen(n-1)cdots (n-k+1)^k; factorsn^k= 1cdot left(1-frac1nright)cdots left(1-frack-1nright)stackreln to inftylongrightarrow 1$$






share|cite|improve this answer









$endgroup$












  • $begingroup$
    Thank you so much. I didn't know it was right there under my eyes.
    $endgroup$
    – billyandr
    2 days ago










  • $begingroup$
    You are welcome. This "not seeing the obvious" just happens once in a while, I think, to all who do maths. So, it is good to have a math platform like this one. :-)
    $endgroup$
    – trancelocation
    2 days ago



















2












$begingroup$

$$a_n=fracn!n^k(n-k)! implies log(a_n)=log(n!)-k log(n)-log((n-k)!)$$



Use Stirling approximation and continue with Taylor series to get
$$log(a_n)=frack(1-k)2 n+Oleft(frac1n^2right)$$ Continue with Taylor
$$a_n=e^log(a_n)=1+frack(1-k)2 n+Oleft(frac1n^2right)$$






share|cite|improve this answer









$endgroup$








  • 1




    $begingroup$
    This has already a slight touch of overkill, hasn't it? :-)
    $endgroup$
    – trancelocation
    2 days ago










  • $begingroup$
    @trancelocation. You are totally right for the limit. One of my manias is to always look at the approach to the limit. Have a look at matheducators.stackexchange.com/questions/8339/… . Cheers :-)
    $endgroup$
    – Claude Leibovici
    2 days ago












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2 Answers
2






active

oldest

votes








2 Answers
2






active

oldest

votes









active

oldest

votes






active

oldest

votes









6












$begingroup$

It is rather obvious if you cancel the factorials:



$$fracn!n^k(n-k)! =fracoverbracen(n-1)cdots (n-k+1)^k; factorsn^k= 1cdot left(1-frac1nright)cdots left(1-frack-1nright)stackreln to inftylongrightarrow 1$$






share|cite|improve this answer









$endgroup$












  • $begingroup$
    Thank you so much. I didn't know it was right there under my eyes.
    $endgroup$
    – billyandr
    2 days ago










  • $begingroup$
    You are welcome. This "not seeing the obvious" just happens once in a while, I think, to all who do maths. So, it is good to have a math platform like this one. :-)
    $endgroup$
    – trancelocation
    2 days ago
















6












$begingroup$

It is rather obvious if you cancel the factorials:



$$fracn!n^k(n-k)! =fracoverbracen(n-1)cdots (n-k+1)^k; factorsn^k= 1cdot left(1-frac1nright)cdots left(1-frack-1nright)stackreln to inftylongrightarrow 1$$






share|cite|improve this answer









$endgroup$












  • $begingroup$
    Thank you so much. I didn't know it was right there under my eyes.
    $endgroup$
    – billyandr
    2 days ago










  • $begingroup$
    You are welcome. This "not seeing the obvious" just happens once in a while, I think, to all who do maths. So, it is good to have a math platform like this one. :-)
    $endgroup$
    – trancelocation
    2 days ago














6












6








6





$begingroup$

It is rather obvious if you cancel the factorials:



$$fracn!n^k(n-k)! =fracoverbracen(n-1)cdots (n-k+1)^k; factorsn^k= 1cdot left(1-frac1nright)cdots left(1-frack-1nright)stackreln to inftylongrightarrow 1$$






share|cite|improve this answer









$endgroup$



It is rather obvious if you cancel the factorials:



$$fracn!n^k(n-k)! =fracoverbracen(n-1)cdots (n-k+1)^k; factorsn^k= 1cdot left(1-frac1nright)cdots left(1-frack-1nright)stackreln to inftylongrightarrow 1$$







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered 2 days ago









trancelocationtrancelocation

14.1k1829




14.1k1829











  • $begingroup$
    Thank you so much. I didn't know it was right there under my eyes.
    $endgroup$
    – billyandr
    2 days ago










  • $begingroup$
    You are welcome. This "not seeing the obvious" just happens once in a while, I think, to all who do maths. So, it is good to have a math platform like this one. :-)
    $endgroup$
    – trancelocation
    2 days ago

















  • $begingroup$
    Thank you so much. I didn't know it was right there under my eyes.
    $endgroup$
    – billyandr
    2 days ago










  • $begingroup$
    You are welcome. This "not seeing the obvious" just happens once in a while, I think, to all who do maths. So, it is good to have a math platform like this one. :-)
    $endgroup$
    – trancelocation
    2 days ago
















$begingroup$
Thank you so much. I didn't know it was right there under my eyes.
$endgroup$
– billyandr
2 days ago




$begingroup$
Thank you so much. I didn't know it was right there under my eyes.
$endgroup$
– billyandr
2 days ago












$begingroup$
You are welcome. This "not seeing the obvious" just happens once in a while, I think, to all who do maths. So, it is good to have a math platform like this one. :-)
$endgroup$
– trancelocation
2 days ago





$begingroup$
You are welcome. This "not seeing the obvious" just happens once in a while, I think, to all who do maths. So, it is good to have a math platform like this one. :-)
$endgroup$
– trancelocation
2 days ago












2












$begingroup$

$$a_n=fracn!n^k(n-k)! implies log(a_n)=log(n!)-k log(n)-log((n-k)!)$$



Use Stirling approximation and continue with Taylor series to get
$$log(a_n)=frack(1-k)2 n+Oleft(frac1n^2right)$$ Continue with Taylor
$$a_n=e^log(a_n)=1+frack(1-k)2 n+Oleft(frac1n^2right)$$






share|cite|improve this answer









$endgroup$








  • 1




    $begingroup$
    This has already a slight touch of overkill, hasn't it? :-)
    $endgroup$
    – trancelocation
    2 days ago










  • $begingroup$
    @trancelocation. You are totally right for the limit. One of my manias is to always look at the approach to the limit. Have a look at matheducators.stackexchange.com/questions/8339/… . Cheers :-)
    $endgroup$
    – Claude Leibovici
    2 days ago
















2












$begingroup$

$$a_n=fracn!n^k(n-k)! implies log(a_n)=log(n!)-k log(n)-log((n-k)!)$$



Use Stirling approximation and continue with Taylor series to get
$$log(a_n)=frack(1-k)2 n+Oleft(frac1n^2right)$$ Continue with Taylor
$$a_n=e^log(a_n)=1+frack(1-k)2 n+Oleft(frac1n^2right)$$






share|cite|improve this answer









$endgroup$








  • 1




    $begingroup$
    This has already a slight touch of overkill, hasn't it? :-)
    $endgroup$
    – trancelocation
    2 days ago










  • $begingroup$
    @trancelocation. You are totally right for the limit. One of my manias is to always look at the approach to the limit. Have a look at matheducators.stackexchange.com/questions/8339/… . Cheers :-)
    $endgroup$
    – Claude Leibovici
    2 days ago














2












2








2





$begingroup$

$$a_n=fracn!n^k(n-k)! implies log(a_n)=log(n!)-k log(n)-log((n-k)!)$$



Use Stirling approximation and continue with Taylor series to get
$$log(a_n)=frack(1-k)2 n+Oleft(frac1n^2right)$$ Continue with Taylor
$$a_n=e^log(a_n)=1+frack(1-k)2 n+Oleft(frac1n^2right)$$






share|cite|improve this answer









$endgroup$



$$a_n=fracn!n^k(n-k)! implies log(a_n)=log(n!)-k log(n)-log((n-k)!)$$



Use Stirling approximation and continue with Taylor series to get
$$log(a_n)=frack(1-k)2 n+Oleft(frac1n^2right)$$ Continue with Taylor
$$a_n=e^log(a_n)=1+frack(1-k)2 n+Oleft(frac1n^2right)$$







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered 2 days ago









Claude LeiboviciClaude Leibovici

126k1158135




126k1158135







  • 1




    $begingroup$
    This has already a slight touch of overkill, hasn't it? :-)
    $endgroup$
    – trancelocation
    2 days ago










  • $begingroup$
    @trancelocation. You are totally right for the limit. One of my manias is to always look at the approach to the limit. Have a look at matheducators.stackexchange.com/questions/8339/… . Cheers :-)
    $endgroup$
    – Claude Leibovici
    2 days ago













  • 1




    $begingroup$
    This has already a slight touch of overkill, hasn't it? :-)
    $endgroup$
    – trancelocation
    2 days ago










  • $begingroup$
    @trancelocation. You are totally right for the limit. One of my manias is to always look at the approach to the limit. Have a look at matheducators.stackexchange.com/questions/8339/… . Cheers :-)
    $endgroup$
    – Claude Leibovici
    2 days ago








1




1




$begingroup$
This has already a slight touch of overkill, hasn't it? :-)
$endgroup$
– trancelocation
2 days ago




$begingroup$
This has already a slight touch of overkill, hasn't it? :-)
$endgroup$
– trancelocation
2 days ago












$begingroup$
@trancelocation. You are totally right for the limit. One of my manias is to always look at the approach to the limit. Have a look at matheducators.stackexchange.com/questions/8339/… . Cheers :-)
$endgroup$
– Claude Leibovici
2 days ago





$begingroup$
@trancelocation. You are totally right for the limit. One of my manias is to always look at the approach to the limit. Have a look at matheducators.stackexchange.com/questions/8339/… . Cheers :-)
$endgroup$
– Claude Leibovici
2 days ago


















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