Skip to main content
mathmandan's user avatar
mathmandan's user avatar
mathmandan's user avatar
mathmandan
  • Member for 9 years, 6 months
  • Last seen this week
11 votes

Prove $0! = 1$ from first principles

10 votes
Accepted

Evaluate $\int\sqrt[5]{\frac{x+5}{x-5}}\,\mathrm dx$

9 votes

Are all finite-dimensional algebras of a fixed dimension over a field isomorphic to one another?

8 votes

Is every arrangement reachable by shuffling this way?

6 votes

Is every subset of a product a product of subsets?

6 votes
Accepted

Calculating the limit: $\lim \limits_{x \to 0}$ $\frac{\ln(\frac{\sin x}{x})}{x^2}. $

5 votes

Solving a trigonometric equation

4 votes
Accepted

Prove that the series still converges under a permutation

4 votes

Let $G$ be an Abelian group with odd order. Show that $\varphi : G \to G$ such that $\varphi(x)=x^2$ is an automorphism

4 votes
Accepted

Find value of sum of reciprocals of powers of a number

4 votes
Accepted

Make new countable sets from old ones.

3 votes

I have a question about integrating, and what to do about the constant. $\int\frac{1}{1-z}dz$

3 votes

Why $d(x) + d(y) \le n$ when proving Mantel's theorem

3 votes
Accepted

A question on the relation of the Galois group as field automorphisms and the Galois group as permutations of roots

3 votes

Why is $\arctan(x)=x-x^3/3+x^5/5-x^7/7+\dots$?

3 votes
Accepted

Property of odd ordered elements of a Group

3 votes

Showing that there is a point belonging to $2000$ sets.

3 votes

How many ways are there to split $10$ people into two groups of $5$?

2 votes

Reference Needed: $m$-faced dice with $n$ options

2 votes

What is the optimal solution to a 3 Hexagon "Game"

2 votes

Is there a term for a magma with identity (only)?

2 votes

Product topology, projection mappings & compactness

2 votes

6-team Round Robin

2 votes

Derivative of the median?

2 votes

Sum and Divisibility Puzzle

2 votes
Accepted

Showing something is well-defined

2 votes

A puzzle about a sum and product of two numbers

2 votes
Accepted

Cryptography question

2 votes
Accepted

Borel sets and absolutely continuous functions

2 votes

Does ${(x,y)\in\mathbb{R}\times\mathbb{R}:x,y\in\mathbb{Z}}$ have cardinality $\aleph_0$ or $c$?