Limit involving logarithms and exponentials
Clash Royale CLAN TAG#URR8PPP
up vote
0
down vote
favorite
How do I calculate:
$$lim limits_n to inftyleft(1-e^left(fract+ log^2(n)1-log(n)right)right)^n$$
It's from a Statistics exercise, I haven't done analysis for a long time.
I think what I have to do is try to get it to look something like
$$lim limits_n to inftyleft(1+fracAnright)^n$$ for a suitable $A$ and apply the standard limit $$lim limits_n to inftyleft(1+fracAnright)^n = e^A$$ I am stuck though.
limits analysis
add a comment |Â
up vote
0
down vote
favorite
How do I calculate:
$$lim limits_n to inftyleft(1-e^left(fract+ log^2(n)1-log(n)right)right)^n$$
It's from a Statistics exercise, I haven't done analysis for a long time.
I think what I have to do is try to get it to look something like
$$lim limits_n to inftyleft(1+fracAnright)^n$$ for a suitable $A$ and apply the standard limit $$lim limits_n to inftyleft(1+fracAnright)^n = e^A$$ I am stuck though.
limits analysis
add a comment |Â
up vote
0
down vote
favorite
up vote
0
down vote
favorite
How do I calculate:
$$lim limits_n to inftyleft(1-e^left(fract+ log^2(n)1-log(n)right)right)^n$$
It's from a Statistics exercise, I haven't done analysis for a long time.
I think what I have to do is try to get it to look something like
$$lim limits_n to inftyleft(1+fracAnright)^n$$ for a suitable $A$ and apply the standard limit $$lim limits_n to inftyleft(1+fracAnright)^n = e^A$$ I am stuck though.
limits analysis
How do I calculate:
$$lim limits_n to inftyleft(1-e^left(fract+ log^2(n)1-log(n)right)right)^n$$
It's from a Statistics exercise, I haven't done analysis for a long time.
I think what I have to do is try to get it to look something like
$$lim limits_n to inftyleft(1+fracAnright)^n$$ for a suitable $A$ and apply the standard limit $$lim limits_n to inftyleft(1+fracAnright)^n = e^A$$ I am stuck though.
limits analysis
edited 6 hours ago
Davide Morgante
1,566118
1,566118
asked 6 hours ago
Noppawee Apichonpongpan
321413
321413
add a comment |Â
add a comment |Â
1 Answer
1
active
oldest
votes
up vote
0
down vote
First note that as $ntoinfty$ we have
beginalign
fract+ log^2(n)1-log(n)
&sim-log(n)\
&to-infty
endalign
hence $e^fract+ log^2(n)1-log(n)to 0$.
Since $log(1+varepsilon)simvarepsilon$ as $varepsilonto 0$, by taking logarithm, we have
beginalign
lim_n to inftylogleft(1-e^fract+ log^2(n)1-log(n)right)^n
&=lim_n to inftynlogleft(1-e^fract+ log^2(n)1-log(n)right)\
&sim -ne^fract+ log^2(n)1-log(n)
endalign
By taking logarithm again:
beginalign
lim_n to inftylogleft(ne^fract+ log^2(n)1-log(n)right)
&=log n+fract+ log^2(n)1-log(n)\
&=fract+log(n)1-log(n)\
&to -1
endalign
Consequently,
$$lim_ntoinftyleft(1-e^fract+ log^2(n)1-log(n)right)^n=e^-1/e$$
add a comment |Â
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
First note that as $ntoinfty$ we have
beginalign
fract+ log^2(n)1-log(n)
&sim-log(n)\
&to-infty
endalign
hence $e^fract+ log^2(n)1-log(n)to 0$.
Since $log(1+varepsilon)simvarepsilon$ as $varepsilonto 0$, by taking logarithm, we have
beginalign
lim_n to inftylogleft(1-e^fract+ log^2(n)1-log(n)right)^n
&=lim_n to inftynlogleft(1-e^fract+ log^2(n)1-log(n)right)\
&sim -ne^fract+ log^2(n)1-log(n)
endalign
By taking logarithm again:
beginalign
lim_n to inftylogleft(ne^fract+ log^2(n)1-log(n)right)
&=log n+fract+ log^2(n)1-log(n)\
&=fract+log(n)1-log(n)\
&to -1
endalign
Consequently,
$$lim_ntoinftyleft(1-e^fract+ log^2(n)1-log(n)right)^n=e^-1/e$$
add a comment |Â
up vote
0
down vote
First note that as $ntoinfty$ we have
beginalign
fract+ log^2(n)1-log(n)
&sim-log(n)\
&to-infty
endalign
hence $e^fract+ log^2(n)1-log(n)to 0$.
Since $log(1+varepsilon)simvarepsilon$ as $varepsilonto 0$, by taking logarithm, we have
beginalign
lim_n to inftylogleft(1-e^fract+ log^2(n)1-log(n)right)^n
&=lim_n to inftynlogleft(1-e^fract+ log^2(n)1-log(n)right)\
&sim -ne^fract+ log^2(n)1-log(n)
endalign
By taking logarithm again:
beginalign
lim_n to inftylogleft(ne^fract+ log^2(n)1-log(n)right)
&=log n+fract+ log^2(n)1-log(n)\
&=fract+log(n)1-log(n)\
&to -1
endalign
Consequently,
$$lim_ntoinftyleft(1-e^fract+ log^2(n)1-log(n)right)^n=e^-1/e$$
add a comment |Â
up vote
0
down vote
up vote
0
down vote
First note that as $ntoinfty$ we have
beginalign
fract+ log^2(n)1-log(n)
&sim-log(n)\
&to-infty
endalign
hence $e^fract+ log^2(n)1-log(n)to 0$.
Since $log(1+varepsilon)simvarepsilon$ as $varepsilonto 0$, by taking logarithm, we have
beginalign
lim_n to inftylogleft(1-e^fract+ log^2(n)1-log(n)right)^n
&=lim_n to inftynlogleft(1-e^fract+ log^2(n)1-log(n)right)\
&sim -ne^fract+ log^2(n)1-log(n)
endalign
By taking logarithm again:
beginalign
lim_n to inftylogleft(ne^fract+ log^2(n)1-log(n)right)
&=log n+fract+ log^2(n)1-log(n)\
&=fract+log(n)1-log(n)\
&to -1
endalign
Consequently,
$$lim_ntoinftyleft(1-e^fract+ log^2(n)1-log(n)right)^n=e^-1/e$$
First note that as $ntoinfty$ we have
beginalign
fract+ log^2(n)1-log(n)
&sim-log(n)\
&to-infty
endalign
hence $e^fract+ log^2(n)1-log(n)to 0$.
Since $log(1+varepsilon)simvarepsilon$ as $varepsilonto 0$, by taking logarithm, we have
beginalign
lim_n to inftylogleft(1-e^fract+ log^2(n)1-log(n)right)^n
&=lim_n to inftynlogleft(1-e^fract+ log^2(n)1-log(n)right)\
&sim -ne^fract+ log^2(n)1-log(n)
endalign
By taking logarithm again:
beginalign
lim_n to inftylogleft(ne^fract+ log^2(n)1-log(n)right)
&=log n+fract+ log^2(n)1-log(n)\
&=fract+log(n)1-log(n)\
&to -1
endalign
Consequently,
$$lim_ntoinftyleft(1-e^fract+ log^2(n)1-log(n)right)^n=e^-1/e$$
answered 5 hours ago
Fabio Lucchini
5,55411025
5,55411025
add a comment |Â
add a comment |Â
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2873225%2flimit-involving-logarithms-and-exponentials%23new-answer', 'question_page');
);
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password