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May
7
comment Compute the square root of $2$ in $R=\mathbb{Z}/n\mathbb{Z}$ where $n=2^s+1$ and $s=2^k$
The reason I am so curious is because @Justin's formula and the entire discussion here doesn't care that $n$ is a Fermat number, but only that $n$ is divisible by 4.
May
7
comment Compute the square root of $2$ in $R=\mathbb{Z}/n\mathbb{Z}$ where $n=2^s+1$ and $s=2^k$
@Jyrki : Is there a danger that $ux \equiv -x$, i.e. that there might be repeats among $x,-x,ux,-ux$?
May
7
comment Compute the square root of $2$ in $R=\mathbb{Z}/n\mathbb{Z}$ where $n=2^s+1$ and $s=2^k$
Sorry, what I meant was that there are for sure 2 distinct solutions given by $x_1=2^{2^{k-2}}(2^{2^{k-1}}-1)$ and $x_2=2^{2^k}+1-x_1$. I was wondering if there are other roots besides these 2, I can't seem to find an argument against such a possibility.
May
7
comment Compute the square root of $2$ in $R=\mathbb{Z}/n\mathbb{Z}$ where $n=2^s+1$ and $s=2^k$
EDIT: Sorry for the double comment.
May
7
comment Compute the square root of $2$ in $R=\mathbb{Z}/n\mathbb{Z}$ where $n=2^s+1$ and $s=2^k$
Is there another square root besides the $\pm$ of the solution above?
May
6
accepted Non-uniqueness of solutions of the heat equation
May
6
accepted Generalized addition function
May
6
comment Generalized addition function
Your solution is correct, I made a mistake in my last edit, there is no problem with the last statement in its current form.
May
6
revised Generalized addition function
deleted 393 characters in body
May
5
revised Generalized addition function
added 397 characters in body
May
5
comment Generalized addition function
$(-x)\oplus 0= x\oplus 0$ is a desired property
May
5
comment Generalized addition function
About the $0$, $0\oplus 0=(0+0)0\oplus 0=0$.
May
4
comment Generalized addition function
Thanks, I have changed the fourth condition to avoid this inconsistency.
May
4
revised Generalized addition function
added 105 characters in body
May
4
comment Generalized addition function
Thanks, I added it in the statement of the problem.
May
4
revised Generalized addition function
added 73 characters in body
May
4
asked Generalized addition function
Apr
27
comment Deriving the exponential distribution from a shift property of its expectation (equivalent to memorylessness).
I don't think $f$ is uniquely determined. It cannot be derived from the differential equation $F(a)+\mu F'(a)=1$ since this equation is not valid on a set of measure zero. At least I don't know how to solve such equations. I agree that the exponential distribution is a solution to the above problem. I have a feeling that it might not be unique and I'd like to have an argument for or against my feeling...
Apr
26
comment Deriving the exponential distribution from a shift property of its expectation (equivalent to memorylessness).
Thank you for replying, I'd love a clarification for my own self. Correct me if I'm wrong, but I thought that the FTOC can only guarantee that the derivative exists almost everywhere. This implies that the first order differential equation is only almost everywhere satisfied by $F(x)$, and therefore is not uniquely given by the exponential solution any more.
Apr
26
answered A Question on Outer Measure