$left{x:f(x)neq 0right}$ decomposes into a numerable union of sets of finite measurement. with $f$ complex...












0












$begingroup$


Let $f$ function with valued in $mathbb{C}$ and $fin L^1(mathbb{R})$. The set $left{x:f(x)neq 0right}$ decomposes into a numerable union of sets of
Finite measurement.



I want
$left{x:f(x)neq 0right}=bigcup_{nin mathbb{N}} left{x:|f(x)|>1/nright} $
But I do not know if this applies in this case with complex values ​​...










share|cite|improve this question











$endgroup$












  • $begingroup$
    I have already corrected it
    $endgroup$
    – eraldcoil
    Jan 10 at 18:34






  • 1




    $begingroup$
    In which case the result is true, simply because $f(x)=0$ iff there existed $ninmathbb N$ such that $|f| > 1/n $ (even for complex valued $f$)
    $endgroup$
    – Calvin Khor
    Jan 10 at 18:36






  • 1




    $begingroup$
    (...should be $neq 0$ instead of $=0$)
    $endgroup$
    – Calvin Khor
    Jan 10 at 18:56










  • $begingroup$
    In mi notes, say $f(x)neq 0$...
    $endgroup$
    – eraldcoil
    Jan 10 at 19:02






  • 1




    $begingroup$
    I was correcting my comment that was too old for me to edit. Do you understand ?
    $endgroup$
    – Calvin Khor
    Jan 10 at 19:03
















0












$begingroup$


Let $f$ function with valued in $mathbb{C}$ and $fin L^1(mathbb{R})$. The set $left{x:f(x)neq 0right}$ decomposes into a numerable union of sets of
Finite measurement.



I want
$left{x:f(x)neq 0right}=bigcup_{nin mathbb{N}} left{x:|f(x)|>1/nright} $
But I do not know if this applies in this case with complex values ​​...










share|cite|improve this question











$endgroup$












  • $begingroup$
    I have already corrected it
    $endgroup$
    – eraldcoil
    Jan 10 at 18:34






  • 1




    $begingroup$
    In which case the result is true, simply because $f(x)=0$ iff there existed $ninmathbb N$ such that $|f| > 1/n $ (even for complex valued $f$)
    $endgroup$
    – Calvin Khor
    Jan 10 at 18:36






  • 1




    $begingroup$
    (...should be $neq 0$ instead of $=0$)
    $endgroup$
    – Calvin Khor
    Jan 10 at 18:56










  • $begingroup$
    In mi notes, say $f(x)neq 0$...
    $endgroup$
    – eraldcoil
    Jan 10 at 19:02






  • 1




    $begingroup$
    I was correcting my comment that was too old for me to edit. Do you understand ?
    $endgroup$
    – Calvin Khor
    Jan 10 at 19:03














0












0








0





$begingroup$


Let $f$ function with valued in $mathbb{C}$ and $fin L^1(mathbb{R})$. The set $left{x:f(x)neq 0right}$ decomposes into a numerable union of sets of
Finite measurement.



I want
$left{x:f(x)neq 0right}=bigcup_{nin mathbb{N}} left{x:|f(x)|>1/nright} $
But I do not know if this applies in this case with complex values ​​...










share|cite|improve this question











$endgroup$




Let $f$ function with valued in $mathbb{C}$ and $fin L^1(mathbb{R})$. The set $left{x:f(x)neq 0right}$ decomposes into a numerable union of sets of
Finite measurement.



I want
$left{x:f(x)neq 0right}=bigcup_{nin mathbb{N}} left{x:|f(x)|>1/nright} $
But I do not know if this applies in this case with complex values ​​...







real-analysis complex-analysis measure-theory






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 10 at 18:34







eraldcoil

















asked Jan 10 at 18:28









eraldcoileraldcoil

395211




395211












  • $begingroup$
    I have already corrected it
    $endgroup$
    – eraldcoil
    Jan 10 at 18:34






  • 1




    $begingroup$
    In which case the result is true, simply because $f(x)=0$ iff there existed $ninmathbb N$ such that $|f| > 1/n $ (even for complex valued $f$)
    $endgroup$
    – Calvin Khor
    Jan 10 at 18:36






  • 1




    $begingroup$
    (...should be $neq 0$ instead of $=0$)
    $endgroup$
    – Calvin Khor
    Jan 10 at 18:56










  • $begingroup$
    In mi notes, say $f(x)neq 0$...
    $endgroup$
    – eraldcoil
    Jan 10 at 19:02






  • 1




    $begingroup$
    I was correcting my comment that was too old for me to edit. Do you understand ?
    $endgroup$
    – Calvin Khor
    Jan 10 at 19:03


















  • $begingroup$
    I have already corrected it
    $endgroup$
    – eraldcoil
    Jan 10 at 18:34






  • 1




    $begingroup$
    In which case the result is true, simply because $f(x)=0$ iff there existed $ninmathbb N$ such that $|f| > 1/n $ (even for complex valued $f$)
    $endgroup$
    – Calvin Khor
    Jan 10 at 18:36






  • 1




    $begingroup$
    (...should be $neq 0$ instead of $=0$)
    $endgroup$
    – Calvin Khor
    Jan 10 at 18:56










  • $begingroup$
    In mi notes, say $f(x)neq 0$...
    $endgroup$
    – eraldcoil
    Jan 10 at 19:02






  • 1




    $begingroup$
    I was correcting my comment that was too old for me to edit. Do you understand ?
    $endgroup$
    – Calvin Khor
    Jan 10 at 19:03
















$begingroup$
I have already corrected it
$endgroup$
– eraldcoil
Jan 10 at 18:34




$begingroup$
I have already corrected it
$endgroup$
– eraldcoil
Jan 10 at 18:34




1




1




$begingroup$
In which case the result is true, simply because $f(x)=0$ iff there existed $ninmathbb N$ such that $|f| > 1/n $ (even for complex valued $f$)
$endgroup$
– Calvin Khor
Jan 10 at 18:36




$begingroup$
In which case the result is true, simply because $f(x)=0$ iff there existed $ninmathbb N$ such that $|f| > 1/n $ (even for complex valued $f$)
$endgroup$
– Calvin Khor
Jan 10 at 18:36




1




1




$begingroup$
(...should be $neq 0$ instead of $=0$)
$endgroup$
– Calvin Khor
Jan 10 at 18:56




$begingroup$
(...should be $neq 0$ instead of $=0$)
$endgroup$
– Calvin Khor
Jan 10 at 18:56












$begingroup$
In mi notes, say $f(x)neq 0$...
$endgroup$
– eraldcoil
Jan 10 at 19:02




$begingroup$
In mi notes, say $f(x)neq 0$...
$endgroup$
– eraldcoil
Jan 10 at 19:02




1




1




$begingroup$
I was correcting my comment that was too old for me to edit. Do you understand ?
$endgroup$
– Calvin Khor
Jan 10 at 19:03




$begingroup$
I was correcting my comment that was too old for me to edit. Do you understand ?
$endgroup$
– Calvin Khor
Jan 10 at 19:03










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