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Exodd
  • Member for 7 years, 11 months
  • Last seen this week
36 votes
Accepted

Do Fibonacci numbers form a complete residue system in every modulus?

18 votes
Accepted

prove that $ab=1$ implies $ba=1$.

14 votes

Find the norm of the operator $Ax(t)=x(\sqrt{t})$

11 votes

Is the aim of this Tic-Tac-Toe puzzle possible to achieve?

11 votes
Accepted

Some interesting observations on a sum of reciprocals

10 votes
Accepted

Prove that every connected graph of all whose vertices have even degree contain no bridges.

10 votes
Accepted

Can the plane be covered by open disjoint one dimensional intervals?

8 votes
Accepted

Does this set contain an infinite number of prime numbers?

6 votes

Hahn-Banach theorem, dual space

6 votes
Accepted

Dual of a linear program is infeasible

6 votes

How to solve $\omega^4-[(\frac{eB}{m})^2+2\omega_0^2]\omega^2+\omega_0^4=0$ in the simplest way

6 votes
Accepted

Proving $\left|\sin x\right|\leq\frac{(2m+1)!}{2^{4m}(m!)^2}\left[\binom{2m}{m} - \sum_{k=1}^{m} \frac{2}{4k^2-1} \binom{2m}{m+k} \cos(2kx) \right]$

5 votes
Accepted

Reference for trace/norm inequality

5 votes

A group $G$ is finite iff all its elements have the same finite order?

5 votes
Accepted

Proving product of two column stochastic matrices is column stochastic (Proof verification)

5 votes
Accepted

Finding matrices with $A_1^{-1}+A_2^{-1}+...+A_k^{-1}=(A_1+A_2+...+A_k)^{-1}$

5 votes
Accepted

Limit in n-dimensions with dot product

5 votes

Has the point dimension zero or one?

5 votes

Number of divisors of huge numbers

5 votes

$a_n=2^n+3^n+6^n-1$. Find all positive integers that are primes to all terms of the sequence.

5 votes
Accepted

Find the remainder when $1111^{2019}$ is divided by $11111$

5 votes
Accepted

Proving that removing any vector of the linearly dependent set gives a linearly independent set

4 votes
Accepted

If $A$ is $n\times n$ matrix with $(A-I)^2=0$ then which of the following is true?

4 votes
Accepted

$\prod\limits_{i=1}^n \frac{3a_i+2}{2a_i+1}, a_i\geq 1$

4 votes
Accepted

Let $G$ be a disconnected graph of order $n \geq 6$ having three components. Prove that $\Delta(\overline G) \geq \frac{2n}{3}$

4 votes
Accepted

Can anyone give an example for this theorem related to planar graphs?

4 votes
Accepted

$a,b,m,n$ be positive integers such that g.c.d.$(a,b)=1$ and $a^m+b^m|a^n+b^n$ , then $m|n$?

4 votes

Prove the linear independence of $\{\sin^k(x)\}$, $ k\in \mathbb{N}$

4 votes
Accepted

Show $1+\sqrt{5}$ is irreducible in $\mathbb{Z}[\sqrt{5}]$

4 votes

Proving matrices of bilinear forms are congruent

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