Order of $f(x)=frac{3}{-2ln|x|-2ln|x+3|}$ with respect to $x$












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I have $f(x)=frac{3}{-2ln|x|-2ln|x+3|}$ and have to determine the order of this infinitesimal with respect to $x$ for $xto0$.Then it doesn't matter if we are approaching from left or right because $-2ln|x|to+infty$ and : $$lim_{xto0}frac{3}{-2ln|x|x^alpha}$$ But it doesn't seem like for any $alpha$ we can have limit approaching a real number.How can order be determined in that case?










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  • $begingroup$
    What if $alpha <0$?
    $endgroup$
    – Botond
    Jan 26 at 23:01










  • $begingroup$
    If $alphalt0$ we would have $x^alpha$ in numerator with $alphagt0$.But still I don't get by what kind of logic we can have a real valued limit for function.
    $endgroup$
    – Turan Nasibli
    Jan 26 at 23:09










  • $begingroup$
    Can you calculate the limit, for example, when $alpha=-1$?
    $endgroup$
    – Botond
    Jan 27 at 0:08










  • $begingroup$
    @Botond Yes,the limit is equal to $0$
    $endgroup$
    – Turan Nasibli
    Jan 27 at 1:36










  • $begingroup$
    Isn't that a real valued limit?
    $endgroup$
    – Botond
    Jan 27 at 8:59
















0












$begingroup$


I have $f(x)=frac{3}{-2ln|x|-2ln|x+3|}$ and have to determine the order of this infinitesimal with respect to $x$ for $xto0$.Then it doesn't matter if we are approaching from left or right because $-2ln|x|to+infty$ and : $$lim_{xto0}frac{3}{-2ln|x|x^alpha}$$ But it doesn't seem like for any $alpha$ we can have limit approaching a real number.How can order be determined in that case?










share|cite|improve this question











$endgroup$












  • $begingroup$
    What if $alpha <0$?
    $endgroup$
    – Botond
    Jan 26 at 23:01










  • $begingroup$
    If $alphalt0$ we would have $x^alpha$ in numerator with $alphagt0$.But still I don't get by what kind of logic we can have a real valued limit for function.
    $endgroup$
    – Turan Nasibli
    Jan 26 at 23:09










  • $begingroup$
    Can you calculate the limit, for example, when $alpha=-1$?
    $endgroup$
    – Botond
    Jan 27 at 0:08










  • $begingroup$
    @Botond Yes,the limit is equal to $0$
    $endgroup$
    – Turan Nasibli
    Jan 27 at 1:36










  • $begingroup$
    Isn't that a real valued limit?
    $endgroup$
    – Botond
    Jan 27 at 8:59














0












0








0





$begingroup$


I have $f(x)=frac{3}{-2ln|x|-2ln|x+3|}$ and have to determine the order of this infinitesimal with respect to $x$ for $xto0$.Then it doesn't matter if we are approaching from left or right because $-2ln|x|to+infty$ and : $$lim_{xto0}frac{3}{-2ln|x|x^alpha}$$ But it doesn't seem like for any $alpha$ we can have limit approaching a real number.How can order be determined in that case?










share|cite|improve this question











$endgroup$




I have $f(x)=frac{3}{-2ln|x|-2ln|x+3|}$ and have to determine the order of this infinitesimal with respect to $x$ for $xto0$.Then it doesn't matter if we are approaching from left or right because $-2ln|x|to+infty$ and : $$lim_{xto0}frac{3}{-2ln|x|x^alpha}$$ But it doesn't seem like for any $alpha$ we can have limit approaching a real number.How can order be determined in that case?







calculus limits infinitesimals






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share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 26 at 22:54







Turan Nasibli

















asked Jan 26 at 22:37









Turan NasibliTuran Nasibli

846




846












  • $begingroup$
    What if $alpha <0$?
    $endgroup$
    – Botond
    Jan 26 at 23:01










  • $begingroup$
    If $alphalt0$ we would have $x^alpha$ in numerator with $alphagt0$.But still I don't get by what kind of logic we can have a real valued limit for function.
    $endgroup$
    – Turan Nasibli
    Jan 26 at 23:09










  • $begingroup$
    Can you calculate the limit, for example, when $alpha=-1$?
    $endgroup$
    – Botond
    Jan 27 at 0:08










  • $begingroup$
    @Botond Yes,the limit is equal to $0$
    $endgroup$
    – Turan Nasibli
    Jan 27 at 1:36










  • $begingroup$
    Isn't that a real valued limit?
    $endgroup$
    – Botond
    Jan 27 at 8:59


















  • $begingroup$
    What if $alpha <0$?
    $endgroup$
    – Botond
    Jan 26 at 23:01










  • $begingroup$
    If $alphalt0$ we would have $x^alpha$ in numerator with $alphagt0$.But still I don't get by what kind of logic we can have a real valued limit for function.
    $endgroup$
    – Turan Nasibli
    Jan 26 at 23:09










  • $begingroup$
    Can you calculate the limit, for example, when $alpha=-1$?
    $endgroup$
    – Botond
    Jan 27 at 0:08










  • $begingroup$
    @Botond Yes,the limit is equal to $0$
    $endgroup$
    – Turan Nasibli
    Jan 27 at 1:36










  • $begingroup$
    Isn't that a real valued limit?
    $endgroup$
    – Botond
    Jan 27 at 8:59
















$begingroup$
What if $alpha <0$?
$endgroup$
– Botond
Jan 26 at 23:01




$begingroup$
What if $alpha <0$?
$endgroup$
– Botond
Jan 26 at 23:01












$begingroup$
If $alphalt0$ we would have $x^alpha$ in numerator with $alphagt0$.But still I don't get by what kind of logic we can have a real valued limit for function.
$endgroup$
– Turan Nasibli
Jan 26 at 23:09




$begingroup$
If $alphalt0$ we would have $x^alpha$ in numerator with $alphagt0$.But still I don't get by what kind of logic we can have a real valued limit for function.
$endgroup$
– Turan Nasibli
Jan 26 at 23:09












$begingroup$
Can you calculate the limit, for example, when $alpha=-1$?
$endgroup$
– Botond
Jan 27 at 0:08




$begingroup$
Can you calculate the limit, for example, when $alpha=-1$?
$endgroup$
– Botond
Jan 27 at 0:08












$begingroup$
@Botond Yes,the limit is equal to $0$
$endgroup$
– Turan Nasibli
Jan 27 at 1:36




$begingroup$
@Botond Yes,the limit is equal to $0$
$endgroup$
– Turan Nasibli
Jan 27 at 1:36












$begingroup$
Isn't that a real valued limit?
$endgroup$
– Botond
Jan 27 at 8:59




$begingroup$
Isn't that a real valued limit?
$endgroup$
– Botond
Jan 27 at 8:59










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