Alan Simonin
Reputation
752
Top tag
Next privilege 1,000 Rep.
Create new tags
 Dec 30 awarded Yearling May 13 reviewed No Action Needed If A,B are real symmetric positive definite matrices, then $B^{-1} AB$ is symmetric positive definite. Apr 27 reviewed No Action Needed What would base $0$ be? How would/could it work? Apr 19 reviewed No Action Needed Matrix inversion via Levi-Civita symbols Apr 19 reviewed No Action Needed Draw the parallelogram spanned by the vectors. Apr 13 accepted Property of Hausdorff spaces Apr 13 comment Property of Hausdorff spaces I don't think that the neighborhoods have to be open to satisfy the Hausdorff condition. Apr 13 comment Property of Hausdorff spaces Thanks for your comment. As I said to @AsafKaragila, I can now see my mistake. I wanted to prove it that way, but I think it's a dead end. I will do it your way, it is more direct I find. Apr 13 comment Property of Hausdorff spaces Yes you are right, now I can see my mistake. Thanks ! Apr 13 asked Property of Hausdorff spaces Apr 11 reviewed No Action Needed Evaluating arithmetic sum using prime factorization Apr 5 reviewed No Action Needed Iterative (functional) roots of integer functions (functions on $\mathbb{Z}$) Apr 5 reviewed No Action Needed How many digits does the integer zero have? Apr 5 reviewed No Action Needed Example that the union of sigma algebra is not an algebra Mar 21 reviewed No Action Needed Paths and connectivity of graphs Mar 18 reviewed No Action Needed Keep factoring and concatenating to get a prime? Mar 16 comment Proving an equivalence between equalities Thanks for your answer. It is an unusual way of thinking but it gets the job done. And most important, I can use it to prove something rigorously (and not use a Venn's diagram to get convinced) Mar 15 comment Does the function $f(x)=x$, $x\in (0,1)$ have a maximum and minimum value? Here is an intuition why there is no maximum nor minimum value : Suppose you find $x \in (0,1)$ such that $f(x)$ is the maximum. Since $(0,1)$ is an open set, for any x, you can find another point right next to it that is greater. Therefore the maximum was not one and therefore there exist none. Mar 15 reviewed Reviewed Discrete Math - Logic - Implication Problem Mar 15 comment Discrete Math - Logic - Implication Problem Don't write in uppercase, it looks like you are yelling