User gebruiker

29 votes

3 answers

29k views

Derive or differentiate?

asked Jul 10, 2014 at 11:46

15 votes

2 answers

612 views

Is a regular tessellation $\{p,q\}$ always possible on some closed surface $S$?

asked Aug 2, 2017 at 17:54

5 votes

2 answers

2k views

Prove equivalence between $X$ Hausdorff and $X$ finite with discrete topology

asked May 19, 2015 at 17:25

5 votes

2 answers

240 views

Show that $y^2=x^3+1$ has infinitely many solutions over $\mathbb Z_p$.

asked Dec 11, 2015 at 15:27

3 votes

2 answers

705 views

How to make sense of the binomial coefficient over $p$-adic integers?

asked Dec 13, 2015 at 15:57

3 votes

0 answers

125 views

For $\operatorname{char}(R)=\bar n$ and $\bar m<\bar n$, show that $\bar m\cdot x=0$ is only possible in a "trivial" manner.

asked Dec 22, 2015 at 17:09

3 votes

2 answers

162 views

On problems which can be proved easier if we use a different induction step.

asked Sep 26, 2014 at 14:57

3 votes

2 answers

403 views

Question on fields with trival Brauer group

asked Nov 5, 2014 at 15:04

3 votes

1 answer

1k views

Is there a unique inverse for a left-unit?

asked May 23, 2014 at 16:00

3 votes

0 answers

2k views

Difference between a vector space and an algebra

asked May 13, 2014 at 10:06

3 votes

2 answers

78 views

What is $T^nf(t)$? (Question on integrals)

asked Jun 24, 2014 at 15:17

3 votes

2 answers

192 views

Is $x^4+nx+1$ irreducible?

asked May 8, 2015 at 10:05

3 votes

2 answers

374 views

Adding primitive $n^\text{th}$ roots of unity, where $n$ is not square-free.

asked Dec 8, 2015 at 15:10

2 votes

1 answer

76 views

Why should $\frac{2\pi}{5}$-rotations extend to symmetries of this platonically tesselated surface?

asked Jan 30, 2017 at 11:01

2 votes

1 answer

2k views

What's the use of the reduced norm?

asked Sep 17, 2014 at 10:01

2 votes

1 answer

209 views

How to handle the tensor $T^i_{ljk}$, given that $T^i_{jkl}=3T^i_{ljk}$?

asked Jun 20, 2016 at 12:05

2 votes

1 answer

258 views

Decomposition into irreducibles of a Noetherian topological space

asked May 30, 2015 at 14:20

2 votes

1 answer

654 views

Is $K[[x]]$ an Artinian/Noetherian $K[x]$-module?

asked Jun 9, 2015 at 11:41

2 votes

1 answer

2k views

Compute the ring of integers

asked Sep 23, 2015 at 16:32

2 votes

1 answer

122 views

Generating an algebra

asked May 16, 2014 at 14:06

2 votes

1 answer

74 views

Simple module over $A$ has finite dimension over $K$

asked Jun 5, 2014 at 18:49

2 votes

1 answer

430 views

What does an $\oplus$-sign in the superscript mean?

asked Jun 6, 2014 at 14:27

2 votes

1 answer

219 views

What exactly is a skew field extension?

asked Jun 9, 2014 at 10:49

2 votes

1 answer

72 views

Why are these dimensions equal?

asked Jul 21, 2014 at 17:51

1 vote

2 answers

927 views

Scalar multiplication on tensor products

asked Aug 8, 2014 at 15:17

1 vote

1 answer

141 views

Are the norms $\Vert f\Vert_1=\Vert f\Vert _\infty+\Vert f'\Vert _\infty$ and $\Vert f\Vert _2=\vert f(a)\vert +\Vert f'\Vert _\infty$ equivalent?

asked Apr 28, 2014 at 12:17

1 vote

1 answer

129 views

Need help considering series like these: $\sum_{n=1}^\infty\langle x,e_n\rangle e_n$

asked Jul 8, 2014 at 11:09

1 vote

1 answer

1k views

Computing the differental of an orthogonal projection

asked Dec 18, 2014 at 13:36

1 vote

1 answer

32 views

$\bigcap_{j=1}^n m_j\subseteq m_{n+1}\implies \exists j~~ m_j=m_{n+1}$

asked Mar 26, 2015 at 16:02

1 vote

1 answer

296 views

Do we really need Zorn's lemma to prove the existence of prime ideals?

asked Apr 3, 2015 at 13:24

Stack Exchange Network

53 Questions

Derive or differentiate?

Is a regular tessellation $\{p,q\}$ always possible on some closed surface $S$?

Prove equivalence between $X$ Hausdorff and $X$ finite with discrete topology

Show that $y^2=x^3+1$ has infinitely many solutions over $\mathbb Z_p$.

How to make sense of the binomial coefficient over $p$-adic integers?

For $\operatorname{char}(R)=\bar n$ and $\bar m<\bar n$, show that $\bar m\cdot x=0$ is only possible in a "trivial" manner.

On problems which can be proved easier if we use a different induction step.

Question on fields with trival Brauer group

Is there a unique inverse for a left-unit?

Difference between a vector space and an algebra

What is $T^nf(t)$? (Question on integrals)

Is $x^4+nx+1$ irreducible?

Adding primitive $n^\text{th}$ roots of unity, where $n$ is not square-free.

Why should $\frac{2\pi}{5}$-rotations extend to symmetries of this platonically tesselated surface?

What's the use of the reduced norm?

How to handle the tensor $T^i_{ljk}$, given that $T^i_{jkl}=3T^i_{ljk}$?

Decomposition into irreducibles of a Noetherian topological space

Is $K[[x]]$ an Artinian/Noetherian $K[x]$-module?

Compute the ring of integers

Generating an algebra

Simple module over $A$ has finite dimension over $K$

What does an $\oplus$-sign in the superscript mean?

What exactly is a skew field extension?

Why are these dimensions equal?

Scalar multiplication on tensor products

Are the norms $\Vert f\Vert_1=\Vert f\Vert _\infty+\Vert f'\Vert _\infty$ and $\Vert f\Vert _2=\vert f(a)\vert +\Vert f'\Vert _\infty$ equivalent?

Need help considering series like these: $\sum_{n=1}^\infty\langle x,e_n\rangle e_n$

Computing the differental of an orthogonal projection

$\bigcap_{j=1}^n m_j\subseteq m_{n+1}\implies \exists j~~ m_j=m_{n+1}$

Do we really need Zorn's lemma to prove the existence of prime ideals?