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Per Alexandersson
  • Member for 12 years
  • Last seen this week
35 votes

How to study math to really understand it and have a healthy lifestyle with free time?

27 votes

Why is $22/7$ a better approximation for $\pi$ than $3.14$?

8 votes
Accepted

Using permutation matrix to get LU-Factorization with $A=UL$

8 votes

What are some things we can prove they must exist, but have no idea what they are?

7 votes
Accepted

Geometrical meanings of diagonalizable and normal matrices

7 votes

What are the last four digits in the binary expansion $1234^{5555} + 4321^{5555}$?

6 votes

On the growth of the Jacobi theta function

6 votes

Mathematics base for data mining and artificial intelligence algorithms.

5 votes

What is the definition of $\infty$

5 votes

Fields that require both CS and pure math

5 votes

What's the goal of mathematics?

5 votes

Why do we have the notions of both 'norm' and 'metric'?

5 votes

Odds of winning at minesweeper with perfect play

5 votes

Creating a new math symbol?

4 votes

how to solve a system with more equations than unkowns?

4 votes

What's polynomial composition useful for?

4 votes

Understandable questions which are hard for non-mathematicians but easy for mathematicians

4 votes

quasiconformal "automorphism" groups of Julia sets

4 votes
Accepted

What is the "Mathematica" function for plotting a single variable inequality?

4 votes

Why is $\sqrt{\sum_{i=1}^n |v_i|^2} \leq \sum_{i=1}^n |v_i|$ true?

3 votes

Calculating Gröbner basis for Sudoku

3 votes
Accepted

Quick Julia/Mandelbrot Testing

3 votes

Sum and Product of Infinite Radicals

3 votes

Is the set of all $n\times n$ matrices, such that for a fixed matrix B AB=BA, a subspace of the vector space of all $n\times n$ matrices?

3 votes

Prove inequality: When $n > 2$, $n! < {\left(\frac{n+2}{\sqrt{6}}\right)}^n$

3 votes
Accepted

How to write the equation of a line in $\mathbb C^n$?

3 votes

Minimum value of $x+4z$ subject to the constraint $x^2+y^2+z^2\leq 2$?

3 votes
Accepted

Is there an expression for Jack polynomials in terms of the power sum basis?

2 votes
Accepted

Topology: Show by using induction that the finite intersection of $n$ open sets is open.

2 votes

How to show that $\cos\frac{2\pi}{n} + \cos\frac{4\pi}{n} + \ldots+ \cos\frac{2\pi(n-1)}{n} = -1$ for all positive integers $n$?