User Maik Pickl

11 votes

Why is some power of a permutation matrix always the identity?

answered Jun 27, 2016 at 8:08

5 votes

Accepted

Why can't we use the law of cosines to prove Fermat's Last Theorem?

answered Jul 1, 2016 at 13:24

5 votes

Accepted

Partition of unity from RCA Rudin

answered Jun 19, 2016 at 13:15

5 votes

Accepted

Every symmetric bilinear form has a orthogonal basis

answered Aug 1, 2016 at 19:34

5 votes

Inverse limit of finite sets with surjective maps has surjective projection?

answered Aug 3, 2016 at 15:03

4 votes

Accepted

Is a space with the cofinite topology compactly generated?

answered Jun 15, 2016 at 21:25

4 votes

Accepted

Give an example of a ring of cardinality 8 such that there are exactly 6 zero divisors

answered Jun 12, 2016 at 18:02

4 votes

Accepted

The inductive construction of a CW complex.

answered Mar 27, 2016 at 16:51

4 votes

Accepted

Prove: $h \in T_xM \iff \operatorname{dist}(x+\epsilon h,M) = o(\epsilon)$

answered Apr 1, 2016 at 20:37

4 votes

Accepted

injective linear transformation basis.

answered Apr 3, 2016 at 12:47

4 votes

Accepted

Understanding a proof of Schröder-Bernstein theorem

answered Apr 3, 2016 at 23:10

3 votes

If the orbit space is Hausdorff, must the action be proper?

answered Apr 2, 2016 at 11:21

3 votes

Accepted

Show that $\{ \rho(u_n,v_n)\} \rightarrow \rho(u,v)$

answered Mar 30, 2016 at 18:26

3 votes

Accepted

morphism of $C^{\infty}(M)$ algebra

answered Mar 27, 2016 at 22:33

3 votes

Accepted

Linear transformations on finite dimensional spaces

answered Apr 6, 2016 at 7:57

3 votes

Proof about characteristic polynomial

answered May 28, 2016 at 10:17

3 votes

Prove or Disprove: there is only one ring homomorphism $f:\mathbb{R} \rightarrow \mathbb{C}$

answered May 31, 2016 at 15:58

3 votes

Accepted

Corollary of Schur's Lemma - why abelian

answered Jul 29, 2016 at 8:42

2 votes

Accepted

Why does $y$ go to $0$ faster than $x$?

answered Aug 19, 2016 at 15:47

2 votes

Show that $T$ has an invariant subspace of dimension $j$ for each $j=1,2,\ldots \dim V$.

answered Jan 13, 2017 at 14:35

2 votes

Let $G$ be the set of all functions $g : ℕ \to \{0,1\}$. Prove that $G$ is uncountable.

answered Jul 13, 2019 at 8:54

2 votes

Accepted

How do I compute this integral of the following $2$ form in $\Bbb{R}^3$.

answered Jan 26, 2022 at 13:34

2 votes

Accepted

What is $M_P/M_P^2$?

answered Dec 9, 2023 at 10:16

2 votes

Accepted

Linear transformation defined by an $m$ by $n$ matrix

answered Jun 14, 2016 at 9:20

2 votes

How to create a counter example of a matrix with non orthogonal eigenvector?

answered Jun 6, 2016 at 14:46

2 votes

Functorial Morphism in Top / Topological Question

answered Jun 8, 2016 at 12:43

2 votes

Accepted

An open set that has no volume

answered Jun 12, 2016 at 12:46

2 votes

Accepted

Any basis of a $C_2$ space admits a countable subcollection as a basis

answered Apr 2, 2016 at 18:46

2 votes

Accepted

Proving that second derivative is perpendicular to curve

answered Apr 2, 2016 at 21:23

2 votes

Accepted

Liouville's Theorem Applications

answered Apr 11, 2016 at 17:06

Stack Exchange Network

79 Answers

Why is some power of a permutation matrix always the identity?

Why can't we use the law of cosines to prove Fermat's Last Theorem?

Partition of unity from RCA Rudin

Every symmetric bilinear form has a orthogonal basis

Inverse limit of finite sets with surjective maps has surjective projection?

Is a space with the cofinite topology compactly generated?

Give an example of a ring of cardinality 8 such that there are exactly 6 zero divisors

The inductive construction of a CW complex.

Prove: $h \in T_xM \iff \operatorname{dist}(x+\epsilon h,M) = o(\epsilon)$

injective linear transformation basis.

Understanding a proof of Schröder-Bernstein theorem

If the orbit space is Hausdorff, must the action be proper?

Show that $\{ \rho(u_n,v_n)\} \rightarrow \rho(u,v)$

morphism of $C^{\infty}(M)$ algebra

Linear transformations on finite dimensional spaces

Proof about characteristic polynomial

Prove or Disprove: there is only one ring homomorphism $f:\mathbb{R} \rightarrow \mathbb{C}$

Corollary of Schur's Lemma - why abelian

Why does $y$ go to $0$ faster than $x$?

Show that $T$ has an invariant subspace of dimension $j$ for each $j=1,2,\ldots \dim V$.

Let $G$ be the set of all functions $g : ℕ \to \{0,1\}$. Prove that $G$ is uncountable.

How do I compute this integral of the following $2$ form in $\Bbb{R}^3$.

What is $M_P/M_P^2$?

Linear transformation defined by an $m$ by $n$ matrix

How to create a counter example of a matrix with non orthogonal eigenvector?

Functorial Morphism in Top / Topological Question

An open set that has no volume

Any basis of a $C_2$ space admits a countable subcollection as a basis

Proving that second derivative is perpendicular to curve

Liouville's Theorem Applications