Stack Exchange

acarchau

top accounts reputation activity bookmarks subscriptions
Top Questions
Top Answers
21
Calculating $\lim_{n\to\infty}\sqrt{n}\sin(\sin…(\sin(x)..)$
math.stackexchange.com

14
How to prove that the rank of a matrix is a lower semi-continuous function?
math.stackexchange.com

13
Can a symmetric matrix always be represented as the sum of a positive-definite and negative-definite matrix?
math.stackexchange.com

11
Measurable function remaining constant
math.stackexchange.com

9
Summation of $\sum\limits_{n=1}^{\infty} \frac{x(x+1) \cdots (x+n-1)}{y(y+1) \cdots (y+n-1)}$
math.stackexchange.com

9
limit of the sum $\frac{1}{n+1}+\frac{1}{n+2}+\cdots+\frac{1}{2n} $
math.stackexchange.com

8
The meaning behind $(X^TX)^{-1}$
math.stackexchange.com

6
Consider the following sequence defined as follows:
math.stackexchange.com

6
Does $\sum_k \frac{a_k-a_{k-1}}{a_k^2}$ converge if $a_k \uparrow \infty$?
math.stackexchange.com

6
How to study $\sum_{n=2}^\infty \ln(1 + 3/n + 3/n^2 + 1/n^3)$
math.stackexchange.com

5
How to prove this binomial identity $\sum_{r=0}^n {r {n \choose r}} = n2^{n-1}$?
math.stackexchange.com

5
Understanding dominating functions
math.stackexchange.com

5
is $f$ surjective from $\mathbb{R}\rightarrow\mathbb{R}$
math.stackexchange.com

5
Does this $3\times 3$ matrix exist?
math.stackexchange.com

5
If $\operatorname{rk}(A) = 1$, when $B + A$ is invertible?
math.stackexchange.com

5
How to write $ uv^{\top} + vu^{\top} $ as $ xx^{\top} + yy^{\top} $?
math.stackexchange.com

5
Printing beamer slides?
tex.stackexchange.com

5
$\lambda^2$ is an eigenvalue of $A^2$. Prove that $\lambda$ or $-\lambda$ is an eigenvalue of the matrix $A$
math.stackexchange.com