Fiktor

Member for 13 years, 4 months
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St. Petersburg, Russia

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real-analysis

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Score Activity Newest

78

Prove that $\prod_{k=1}^{n-1}\sin\frac{k \pi}{n} = \frac{n}{2^{n-1}}$

Oct 30, 2010

7

Proper Measurable subgroups of $\mathbb R$

Aug 4, 2010

6

Cutting the Cake Problem

Aug 14, 2010

6

How do you show that $d\theta = \frac{x dy - y dx }{x^2 + y^2}$?

Oct 5, 2010

5

Packing disjoint family of discs with radii $\tfrac{1}{2}, \tfrac{1}{3}, \tfrac{1}{4},\ldots$ inside the unit disc

Oct 3, 2010

Questions

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31

Fundamental group of GL(n,C) is isomorphic to Z. How to learn to prove facts like this?

Aug 30, 2010

18

Matrix diagonalization theorems and counterexamples: reference-request.

Feb 19, 2014

13

In which commutative algebras does any derivation possess a flow?

Sep 19, 2010

11

Upper-triangular matrix is invertible iff its diagonal is invertible: C*-algebra case

Oct 25, 2010

7

How to prove the following resummation identity for Erdős–Borwein constant?

Sep 6, 2022

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complex-numbers

78

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products

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roots-of-unity

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trigonometry

78

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real-analysis

18

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5

posts

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+10

Computational complexity of colored vector space isomorphism over the binary field

+10

Proper Measurable subgroups of $\mathbb R$

+10

What do all the $k$-cycles in $S_n$ generate?

+10

In which commutative algebras does any derivation possess a flow?

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