User Taladris

99 votes

4 answers

21k views

Why did no student correctly find a pair of $2\times 2$ matrices with the same determinant and trace that are not similar?

asked Apr 10, 2017 at 1:37

35 votes

5 answers

2k views

Total distance traveled when visiting all rational numbers

asked Nov 8, 2016 at 3:53

32 votes

5 answers

4k views

Why is "mathematical induction" called "mathematical"?

asked Dec 25, 2014 at 7:56

18 votes

1 answer

3k views

Arithmetic and geometric sequences: where does their name come from?

asked Jun 4, 2014 at 17:30

15 votes

1 answer

1k views

How did Vladimir Voevodsky "changed the meaning of the equals sign"?

asked Oct 7, 2017 at 13:11

15 votes

2 answers

1k views

Can we recover the adjacency matrix of a graph from its square?

asked Jan 26, 2022 at 7:43

11 votes

2 answers

491 views

Indefinite integral. Where is the mistake?

asked Nov 1, 2013 at 1:36

10 votes

1 answer

2k views

Simplicial homology of the skeleton of a simplex

asked Jul 28, 2014 at 4:43

8 votes

1 answer

160 views

Where to place 10 guards in a 17-walled art gallery such that removal of any one leaves the gallery unprotected?

asked Sep 12, 2018 at 4:30

7 votes

1 answer

2k views

Is there a strategy to win this "move color" game?

asked Feb 17, 2021 at 15:11

7 votes

2 answers

208 views

What can be said about the set of points that makes the MVT "works"?

asked Oct 17, 2017 at 9:07

7 votes

3 answers

512 views

Nice embedding of the permutohedron of order $n$ in ${\mathbb R}^{n-1}$

asked Apr 26, 2015 at 8:05

7 votes

1 answer

314 views

Why do we care about planar graphs?

asked Dec 28, 2022 at 7:50

6 votes

4 answers

890 views

Geometric proof that $\int_a^c (x-a)(x-b)(x-c)\ dx=0$ if and only if $b$ is the midpoint of $a$ and $c$.

asked Oct 28, 2015 at 6:08

6 votes

2 answers

354 views

Interval of convergence of $\sum\limits_{n\geq0} \binom{2n}{n} x^n$

asked Jun 8, 2013 at 3:13

6 votes

2 answers

4k views

Intuitive idea behind the probability density function

asked Mar 12, 2014 at 7:38

6 votes

1 answer

471 views

Can we prove that an odd degree real polynomial has a root from Descartes' Rule of Signs?

asked Sep 12, 2017 at 4:27

5 votes

2 answers

142 views

Non analytic numbers

asked Mar 5, 2014 at 4:07

5 votes

0 answers

404 views

Examples of good phone interview quetions.

asked Nov 17, 2013 at 4:50

5 votes

2 answers

1k views

Piecewise linear function and absolute value

asked Aug 30, 2014 at 9:53

5 votes

1 answer

1k views

Converse of the Fundamental Theorem of Calculus

asked Oct 6, 2014 at 6:15

5 votes

1 answer

4k views

L'Hospital's rule vs Taylor series

asked May 20, 2014 at 16:29

5 votes

2 answers

521 views

How to recover the cohomology of a torus from its description of a quotient

asked Jul 27, 2015 at 1:32

4 votes

1 answer

285 views

Exterior powers of vector space and kernel

asked Aug 7, 2015 at 6:26

4 votes

1 answer

100 views

Counter-example to $\int_0^\infty f(x) dx=\lim_{t\to\infty} \int_{1/t}^t f(x) dx$

asked Apr 1, 2015 at 5:44

4 votes

6 answers

4k views

Logic and set theory textbook for high school

asked Jan 17, 2014 at 2:50

4 votes

0 answers

550 views

Upper bound for area of polygons

asked Feb 3, 2014 at 5:44

4 votes

2 answers

562 views

Prove or disprove: For $2\times 2$ matrices $A$ and $B$, if $(AB)^2=0$, then $(BA)^2=0$.

asked Mar 15, 2016 at 1:55

4 votes

1 answer

434 views

Counter-example for integration by parts with improper integrals

asked Apr 30, 2020 at 8:27

4 votes

1 answer

92 views

Are there invertible functions such that $f=\frac{g}{h}$ and $f^{-1}=\frac{g^{-1}}{h^{-1}}$?

asked Jul 6, 2020 at 5:44

Stack Exchange Network

78 Questions

Why did no student correctly find a pair of $2\times 2$ matrices with the same determinant and trace that are not similar?

Total distance traveled when visiting all rational numbers

Why is "mathematical induction" called "mathematical"?

Arithmetic and geometric sequences: where does their name come from?

How did Vladimir Voevodsky "changed the meaning of the equals sign"?

Can we recover the adjacency matrix of a graph from its square?

Indefinite integral. Where is the mistake?

Simplicial homology of the skeleton of a simplex

Where to place 10 guards in a 17-walled art gallery such that removal of any one leaves the gallery unprotected?

Is there a strategy to win this "move color" game?

What can be said about the set of points that makes the MVT "works"?

Nice embedding of the permutohedron of order $n$ in ${\mathbb R}^{n-1}$

Why do we care about planar graphs?

Geometric proof that $\int_a^c (x-a)(x-b)(x-c)\ dx=0$ if and only if $b$ is the midpoint of $a$ and $c$.

Interval of convergence of $\sum\limits_{n\geq0} \binom{2n}{n} x^n$

Intuitive idea behind the probability density function

Can we prove that an odd degree real polynomial has a root from Descartes' Rule of Signs?

Non analytic numbers

Examples of good phone interview quetions.

Piecewise linear function and absolute value

Converse of the Fundamental Theorem of Calculus

L'Hospital's rule vs Taylor series

How to recover the cohomology of a torus from its description of a quotient

Exterior powers of vector space and kernel

Counter-example to $\int_0^\infty f(x) dx=\lim_{t\to\infty} \int_{1/t}^t f(x) dx$

Logic and set theory textbook for high school

Upper bound for area of polygons

Prove or disprove: For $2\times 2$ matrices $A$ and $B$, if $(AB)^2=0$, then $(BA)^2=0$.

Counter-example for integration by parts with improper integrals

Are there invertible functions such that $f=\frac{g}{h}$ and $f^{-1}=\frac{g^{-1}}{h^{-1}}$?