Skip to main content
Noah Stein's user avatar
Noah Stein's user avatar
Noah Stein's user avatar
Noah Stein
  • Member for 13 years, 10 months
  • Last seen more than 3 years ago
24 votes
Accepted

Slowing down divergence 2

19 votes

prove that $\frac{(2n)!}{(n!)^2}$ is even if $n$ is a positive integer

19 votes
Accepted

Why is convexity more important than quasi-convexity in optimization?

18 votes

Are there real-life relations which are symmetric and reflexive but not transitive?

16 votes

Disjoint convex sets that are not strictly separated

15 votes

How many digits are there in $2^{100}$?

13 votes

Prove by Combinatorial Argument that $\binom{n}{k}= \frac{n}{k} \binom{n-1}{k-1}$

11 votes

How to prove absolute summability of sinc function?

9 votes
Accepted

Is there a way to represent the interior of a circle with a curve?

9 votes

A practical way to check if a matrix is positive-definite

9 votes
Accepted

pythagoras theorem for $L_p$ spaces

8 votes

prove that $E(f(X,Y)|X) = E(f(X,Y))$

8 votes
Accepted

Is there any thing like matrices for three-dimensional linear algebra?

7 votes

Inductive proof that $(m!^n)n! \mid (mn)!$

6 votes
Accepted

Finding Nash equilibria using Support Enumeration

6 votes

"Converse" of Taylor's theorem

6 votes
Accepted

Completion of Topological Group with Metric

6 votes

How can I prove that this function is continuous at $0$?

6 votes

Converting recursive function to closed form

6 votes
Accepted

symmetric positive definite matrices

5 votes
Accepted

A basis for the dual space of $V$

4 votes
Accepted

Non-linear function on $\mathbb{R}^2$ preserving the origin and maps lines onto lines?

4 votes

Measurable subset of $\mathbb{R}$ with a specific property

3 votes

An inequality on a matrix involving a norm and the eigenvalues

3 votes
Accepted

Why are cluster co-occurrence matrices positive semidefinite?

3 votes
Accepted

convexity of inner product of elementwise powers

3 votes
Accepted

Convexity of inverted sum of positive definite matrices

3 votes

trivial but non-trivial equivalence relations

3 votes

What does "working mathematician" mean?

2 votes

Pathologies in module theory