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Jul
4
comment The principle of duality for sets
Thank you, this is exactly what I was looking for. I've been reading up on lattices now it is very interesting. Can you recommend any resources for learning more about lattice theory?
Jul
4
accepted The principle of duality for sets
Jul
1
asked The principle of duality for sets
Jun
28
accepted Is every day tau day (or pi day) to some base?
Jun
28
comment Is every day tau day (or pi day) to some base?
@HagenvonEitzen oh. Duh.
Jun
28
asked Is every day tau day (or pi day) to some base?
Jun
20
accepted Find the Dirichlet inverse of the identity function
Jun
18
asked Find the Dirichlet inverse of the identity function
Jun
13
accepted Using Fermat's Little Theorem, find the least positive residue of $3^{999999999}\mod 7$
Jun
13
asked Using Fermat's Little Theorem, find the least positive residue of $3^{999999999}\mod 7$
May
28
revised If $x\equiv y \pmod{\gcd(a,b)}$, show that there is a unique $z\pmod{\text{lcm}(a,b)}$ with $z\equiv x\pmod a$ and $z\equiv y\pmod b$
edited title
May
28
asked If $x\equiv y \pmod{\gcd(a,b)}$, show that there is a unique $z\pmod{\text{lcm}(a,b)}$ with $z\equiv x\pmod a$ and $z\equiv y\pmod b$
May
28
asked Prove that if $p_1,\dots,p_k$ are distinct odd primes then 1 has $2^k$ square roots $\mod m$ where $m$ is the product of the primes.
May
23
comment Prove that if $n\geq\text{lcm}(a,b)$ and $\gcd(a,b)|n$ then $n=xa+yb$ for some integers $x,y\geq 0$
I'm still rather stuck. I can't quite see how I can show that the coefficients are nonnegative from that. Can you possibly offer any other insight?
May
23
asked Prove that if $n\geq\text{lcm}(a,b)$ and $\gcd(a,b)|n$ then $n=xa+yb$ for some integers $x,y\geq 0$
May
17
awarded  Nice Question
Apr
22
accepted Is a broken clock right twice a day?
Apr
22
comment Are the eigenvalues of $AB$ equal to the eigenvalues of $BA$? (Citation needed!)
I know this is an ancient thread but hopefully you're still lurking out there somewhere. How come you need to hope that $\lambda\ne 0$? Doesn't the argument still work just fine in the case where $\lambda=0$?
Apr
22
comment Is there a nice way to interpret this matrix equation that comes up in the context of least squares
@Dolma thanks I fixed that
Apr
22
revised Is there a nice way to interpret this matrix equation that comes up in the context of least squares
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