Numbra's user avatar
Numbra's user avatar
Numbra's user avatar
Numbra
  • Member for 4 years, 1 month
  • Last seen more than a month ago
4 votes
Accepted

Prove that $f(z)$ is a onto group homomorphism?

4 votes
Accepted

How to solve this system of set equalities?

3 votes

Determine if $1.001^n$ will grow faster than $n^{10}$.

3 votes

Proving prefix/suffix exists for finite automata

3 votes
Accepted

Prove that there is a set S of 10 students containing exactly 1 person from every algebra team and exactly 1 person from every calculus team.

2 votes
Accepted

Negation of the limit of a function involving infinity

2 votes

Calculate all numbers $x ∈ ℤ$ that simultaneously satisfy the following 3 congruences

2 votes
Accepted

Confused with a proof about the simplicity of $A_n$.

2 votes
Accepted

maximal/minimal element on >= relation

2 votes
Accepted

BlackWhite mathematics

2 votes
Accepted

Does the set intersection operation has unit

2 votes

Can the sum of all rationals under a number be finite?

2 votes
Accepted

$\sum^\infty_{n=0}\frac {x^{4n}}{(2n)!}$ is Taylor's series of which function?

2 votes
Accepted

Prove,that there exists bijection between the sets $\{0,1\}^*$ and $\{0,1,2\}^*$

2 votes

if $A=B \cup C$ and $A,B$ are open and $C$ is closed then $C \subset B$?

1 vote

Let $\mathbb{R}$ be a commutative ring with $1$ and $M$ = $(a)$ be a maximal ideal of $R$. I need to show that $a$ is irreducible.

1 vote

First-order formula implying the existence of an infinite branch in a tree

1 vote
Accepted

Show that $s − r = \sup \{ a − a^\prime \vert a, a^\prime \in A \}$ and $r − s = \inf \{a − a^\prime \vert a, a^\prime \in A \}$

1 vote
Accepted

Factorization $a^x-1 | (a^x)^k - 1$

1 vote
Accepted

How can one characterise the subsets of $R^d$ with non-decreasing indicator function?

1 vote
Accepted

Interpretation of $f(x)(1 + o(1))$

1 vote

Number of homomorphisms between $\mathbb{Z}/n\mathbb{Z}$ and $\mathbb{C}^{\times}$

1 vote
Accepted

How do I formally prove $\lim_{x \to\infty}f(x+b)-f(x) = 0$?

1 vote
Accepted

Is the language $L=\{<M>|M \text{ has 24 states}\}$ recursive?

1 vote

find the coordinates of the vectors $(u,v)$ in the ordered basis $B=\{a,b\}$?

1 vote
Accepted

False Interpretation of a logical statement

1 vote

Showing that $\sum_{r=1}^{N} \exp\left(\frac{2\pi irs}{N}\right)=0$ when $0<s<N$

1 vote
Accepted

Prove non computability of a function defined on partial and total functions

1 vote

Is the following result true about complex numbers?

0 votes
Accepted

Show that set of words in NP