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Martin R
  • Member for 9 years, 10 months
  • Last seen this week
  • Germany
18 votes
0 answers
534 views

How large must $f(f(z))-z^2$ be in the unit disk?

11 votes
3 answers
469 views

About a chain rule for Wronskians

10 votes
1 answer
171 views

Do Wronskians have the intermediate value property?

7 votes
3 answers
295 views

Is a rational function which maps all circles/lines to circles/lines a Möbius transformation?

6 votes
1 answer
205 views

On an identity between fractions, related to a determinant by K. Rohn

6 votes
1 answer
91 views

What functions satisfy $\int_a^b f(x) c(x) \, dx \ge 0$ for all convex functions $f$?

5 votes
1 answer
107 views

What is the minimal order of a “sigmoid-like” entire function?

5 votes
1 answer
195 views

$|f'(x)| \le g(x)$ implies $|f(b) - f(a)| \le \int_a^b g(x) dx$, without assuming $f'$ to be integrable.

4 votes
2 answers
475 views

$A = \sum_{n=0}^\infty a_n$ and $b_n \to B$ implies $\sum_{k=0}^n a_k b_{n-k} \to AB$

3 votes
1 answer
134 views

Line segment in triangle is at most as long as the longest side [duplicate]

2 votes
1 answer
218 views

The maximum of polynomials with coefficients of absolute value one on the unit circle

2 votes
1 answer
87 views

On the positivity of solutions of the differential inequality $y'' - y < 0$

0 votes
1 answer
101 views

Relation between two extremal properties of Chebyshev polynomials