Commuting floor functions

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Positive irrational numbers $a,b>0$ are such that $lfloor alfloor bxrfloorrfloor = lfloor blfloor axrfloorrfloor$ for all $x>0$. Must it be that $a=b$?



If $a$ and $b$ are allowed to be rational, this is not always true. For example, we can take $a=1$ and $b=frac12$. It is true that $lfloor x/2rfloor = lfloorlfloor xrfloor/2rfloor$ for any real number $x>0$, as when $2nleq x<2n+2$ for some nonnegative integer $n$, both sides evaluate to $n$.










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    Positive irrational numbers $a,b>0$ are such that $lfloor alfloor bxrfloorrfloor = lfloor blfloor axrfloorrfloor$ for all $x>0$. Must it be that $a=b$?



    If $a$ and $b$ are allowed to be rational, this is not always true. For example, we can take $a=1$ and $b=frac12$. It is true that $lfloor x/2rfloor = lfloorlfloor xrfloor/2rfloor$ for any real number $x>0$, as when $2nleq x<2n+2$ for some nonnegative integer $n$, both sides evaluate to $n$.










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      Positive irrational numbers $a,b>0$ are such that $lfloor alfloor bxrfloorrfloor = lfloor blfloor axrfloorrfloor$ for all $x>0$. Must it be that $a=b$?



      If $a$ and $b$ are allowed to be rational, this is not always true. For example, we can take $a=1$ and $b=frac12$. It is true that $lfloor x/2rfloor = lfloorlfloor xrfloor/2rfloor$ for any real number $x>0$, as when $2nleq x<2n+2$ for some nonnegative integer $n$, both sides evaluate to $n$.










      share|cite|improve this question















      Positive irrational numbers $a,b>0$ are such that $lfloor alfloor bxrfloorrfloor = lfloor blfloor axrfloorrfloor$ for all $x>0$. Must it be that $a=b$?



      If $a$ and $b$ are allowed to be rational, this is not always true. For example, we can take $a=1$ and $b=frac12$. It is true that $lfloor x/2rfloor = lfloorlfloor xrfloor/2rfloor$ for any real number $x>0$, as when $2nleq x<2n+2$ for some nonnegative integer $n$, both sides evaluate to $n$.







      real-analysis algebra-precalculus






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      edited Sep 9 at 1:34

























      asked Sep 8 at 13:24









      pi66

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