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Yury's user avatar
Yury's user avatar
Yury
  • Member for 11 years, 10 months
  • Last seen this week
35 votes
Accepted

Properties of the cone of positive semidefinite matrices

31 votes
Accepted

Infinite expected value of a random variable

21 votes
Accepted

It it possible to "compress" a list of large numbers using their prime factors?

14 votes

Taylor expansion of $e^{\cos x}$

12 votes
Accepted

Confusion between principal ideal and ideal

11 votes
Accepted

Expected value of maximum consecutive distance in a uniformly random permutation

11 votes
Accepted

Planar graph with a chromatic number of 4 where all vertices have a degree of 4.

11 votes

Let $T:V→V$ be a linear transformation satisfying $T^2(v)=-v$ for all $v\in V$. How can we show that $n$ is even?

10 votes
Accepted

pairwise correlation of three random variables

10 votes
Accepted

How find the "how many good dyeing" method

10 votes
Accepted

When $\sin x, \cos x$ are $\mathbb{Q}$-linear combinations of square roots

8 votes
Accepted

Probability every hyperplane contains at most $m/2$ vectors

8 votes

How does an Indefinite Integral = Definite Integral with Variable as Upper Limit?

8 votes
Accepted

Does $\mu^{*}(E)=1$ imply $\mu^{*}(E^{c})=0$ when $\mu$ is an outer measure and the measure of the space is $1$

8 votes

Insightful proofs for Sherman-Morrison Formula and Matrix Determinant Lemma

8 votes

Old graduate analysis qualifying exam question

7 votes

Prove or disprove that $f(x) = \sin x/x$ is uniformly continuous over the interval $(0,1)$?

7 votes
Accepted

$\mathbb{Q}$ is not isomorphic to $\mathbb{Q}^+$

6 votes
Accepted

Olympiad number theory problem

6 votes

Why isn't NP = coNP?

6 votes
Accepted

Convergence domain: $\{(z,w):|z|^2+|w|^2 < 1\}$

6 votes

Axiomatic characterization of the rational numbers

6 votes

Find all polynomials that fix $\mathbb Q$ and the irrationals

6 votes

Finding N elements that are included in as many sets as possible

6 votes
Accepted

Lipschitz property and Lipschitz extension

6 votes
Accepted

Example of a subgroup for normality

6 votes
Accepted

Irreducible polynomials with integer coefficients over Q

5 votes

Intuitively, why does $\lim_{n \to \infty} \frac16 (p_{n - 1} + p_{n - 2} ... + p_{n - 6}) = 2/7$?

5 votes
Accepted

Upper bound on smallest prime $p$ needed to tell two numbers $\leq n$ apart modulo $p$

5 votes
Accepted

Convergence in Central Limit Thorem