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Alex Provost's user avatar
Alex Provost's user avatar
Alex Provost's user avatar
Alex Provost
  • Member for 11 years, 5 months
  • Last seen this week
111 votes

Collection of surprising identities and equations.

102 votes

Prove that the function $\sqrt x$ is uniformly continuous on $\{x\in \mathbb{R} | x \ge 0\}$.

54 votes
Accepted

u-substitution shows 0=1

43 votes
Accepted

Intuition about the semidirect product of groups

21 votes

Polyhedra vs Polytope

20 votes
Accepted

Prove that $x-1$ divides $x^n-1$

20 votes
Accepted

A topology on the set of lines?

20 votes

If $A$ is a $2\times2$ matrix, what is $\det(4A)$ in terms of $\det(A)$?

19 votes

Understanding the tensor-hom adjunction intuitively

15 votes
Accepted

How to understand "tensor" in commutative algebra?

14 votes

What is the term given to two functions when their order of composition does not matter?

14 votes
Accepted

Understanding Hom functions

12 votes
Accepted

Proof the Levi-Civita symbol is a tensor

11 votes
Accepted

Prove $D_{24}$ is not isomorphic to $S_4$.

11 votes
Accepted

Existence of a universal cover of a manifold.

11 votes

Null space of quotient map

10 votes
Accepted

$H$ $\cong$ $K$ and $G/H$ $\cong$ $G'/K$ implies $G$ $\cong$ $G'$?

9 votes
Accepted

proof using the mathematical induction

9 votes
Accepted

How do I show that a subspace of a subspace have less dimensions than the parent subspace?

9 votes
Accepted

How many entries in a symmetric matrix can be chosen independently?

8 votes

Why is the empty set in the standard topology?

8 votes
Accepted

Singular homology: $n$-singular chains are to be thought abstractly or geometrically?

8 votes

A Riemannian manifold with constant sectional curvature is Einstein.

8 votes
Accepted

Showing $NH$ is a subgroup of $G$

7 votes
Accepted

Vector bundles and de Rham cohomology

7 votes
Accepted

What is the identity element of a quotient ring?

7 votes
Accepted

Map from quotient group

7 votes

For a subgroup $H$ of a group $G$, how many cosets are there?

6 votes
Accepted

What does it mean for an inner product to induce a norm?

6 votes

Let $S:=\{A \in M_3(\mathbb Z) :A A^{\top}=I \}$ , then what is the cardinality of $S$?

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