User charmd - Mathematics Stack Exchange

charmd

Member for 7 years, 7 months
Last seen this week

France

16 Questions

Score Activity Newest Views

21 votes

4 answers

12k views

Is a convex function always continuous?

asked Oct 19, 2018 at 8:29

17 votes

2 answers

1k views

Function $f$ such that $|f(x)-f(y)| \ge \sqrt{|x-y|}$

asked Feb 16, 2017 at 20:14

15 votes

1 answer

396 views

Power series converging at $1$ with all derivatives zero

asked Feb 18, 2018 at 12:42

12 votes

0 answers

175 views

Is a product of derivatives still a derivative? [duplicate]

asked Dec 28, 2016 at 21:28

8 votes

3 answers

327 views

Symmetric strategy for 100 prisoners and a light bulb problem

asked Apr 4, 2019 at 14:13

8 votes

1 answer

237 views

Biggest convex set inside a concave unit ball

asked Jun 29, 2020 at 20:05

4 votes

1 answer

676 views

Image of a null set by a Hölder continuous function

asked Jan 5, 2017 at 20:41

3 votes

1 answer

149 views

Function with null integral around every point

asked Mar 21, 2019 at 9:13

3 votes

3 answers

260 views

Are $\mathcal{O}(n)$ and $\mathcal{SO}(n)$ isomorphic?

asked Jul 9, 2017 at 18:52

1 vote

2 answers

68 views

Sequence with bounded sums [closed]

asked Feb 7, 2018 at 19:58

1 vote

2 answers

62 views

Two functions, each the integral of the other

asked Jul 6, 2018 at 13:04

1 vote

1 answer

64 views

Compact planar set with positive area contains cartesian products

asked Jan 4, 2017 at 18:33

1 vote

0 answers

38 views

How are these sums called?

asked Mar 5, 2017 at 7:15

1 vote

3 answers

844 views

Average number of head streaks in $N$ coin tosses

asked Nov 27, 2020 at 23:24

1 vote

1 answer

223 views

Even polynomial having multiple with odd coefficients

asked Nov 5, 2018 at 12:04

0 votes

0 answers

571 views

About the symmetric multilinear maps

asked Sep 24, 2018 at 12:08