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1h
comment A difficult linear algebra Problem
The point of the question is that there's a single $r$ that works for every $n\times n$ matrix $M$ that has some power equal to the identity. If $M^m=I$ then the eigenvalues are roots of unity, so the characteristic polynomial involves cyclotomic polynomials, but also the characteristic polynomial is of degree $n$, so there a limit on which cyclotomic polynomials it can involve. But as others have mentioned, it would be a good idea to tell us where the entries come from.
1h
comment The number of regions created by $k$ hyperplanes
9 edits in a day. Think I'll wait a week, until the problem settles down.
5h
comment To make a polynomial with coefficients in a finite field uniform at random
@snarski, there's no way to define a uniform distribution on a countably infinite set, as these polynomial rings will be.
5h
comment $+$ and $\times $ operations in finite fields are $+$ and $\times $ $mod$ some number
There is (up to isomorphism) one and only one field of 4 elements. I recommend as an exercise that you try to construct it. It has to have a 0, and a 1, and you may as well call the other two elements $x$ and $y$; the four elements together must be a group under addition, and the three nonzero elements must be a group under multiplication. With a little effort, you can write out the addition and multiplication tables for this field.
5h
comment Proof in Apostol Polynomial Zeros
Perhaps you could edit your question to incorporate those corrections?
7h
comment Proof in Apostol Polynomial Zeros
Anyway, are you familiar with the Division Theorem? or the Remainder Theorem?
7h
comment Proof in Apostol Polynomial Zeros
Have you left something out? $f(x)=(x-a)h(x)$, maybe? And $n$ is supposed to be ... what?
7h
comment Find Galois Group
The method of @JSchlather isn't guaranteed to work, as there's no guarantee that there will be a 6-cycle. That's what's different about the prime case.
7h
comment $+$ and $\times $ operations in finite fields are $+$ and $\times $ $mod$ some number
Of course, there are finite fields other than ${\bf Z}_n$. There is, for example, a field of 4 elements, and operations in it aren't exactly like operations mod 4, or mod 2 (even though it is true that $a+a=0$ for all $a$ in this field).
7h
comment How to compute dfnumber?
I'm sure your teacher would be happy to explain these things to you. In the meantime, perhaps you could tell us what "dfnumber" and "low number" are?
9h
revised What's known about magic cubes of order 4?
deleted indication of skepticism
11h
comment Legitimate papers refuting the significance of the golden ratio in art?
Have you had a chance to look at Livio's book?
19h
awarded  Refiner
19h
awarded  Explainer
1d
comment Prove there is no surjective homomorphism between $D_4$ (the symmetries of the square) and $Z_4$
Are you familiar, bsm, with The First Isomorphism Theorem? It will get you the answer pretty quickly.
1d
comment A number theoretic inequality
I removed the number-theory tag. I don't see any number-theoretical content here. If you agree, you might want to change the title.
1d
revised A number theoretic inequality
edited tags
1d
comment How to use the fact that $\sum\frac{|\mu (n)|}{n^s}=\frac{\zeta (s)}{\zeta (2s)}$ to determine the number of square free integers below a number?
I say, THE FIRST PART OF YOUR QUESTION IS A DUPLICATE OF THE OLDER QUESTION, NO?
1d
revised Distribution of the RSA numbers
rolled back to a previous revision
1d
comment Find angle x in the picture
I found it --- it's the 3rd upward facing angle from the left!