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Irregular User
  • Member for 8 years, 6 months
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6 votes
3 answers
907 views

Congruent matrices - why do we require invertiblility?

6 votes
1 answer
11k views

Interior of a set is the largest open subset - proof verification

6 votes
3 answers
1k views

Why does the name "epimorphism" refer to a surjective homorphism?

6 votes
1 answer
2k views

Proof of Tychonoff's Theorem for an undergrad

6 votes
1 answer
124 views

The geometry behind the lemniscatic integral: $u' = \int^t_0(4t(1-t^2))^{-1/2}\,dt$

5 votes
0 answers
1k views

Sketching the global phase portrait for a version of the Lotka-Volterra system

5 votes
2 answers
136 views

Is it weird to say $A \in B \in C$?

5 votes
1 answer
2k views

Proof of the Arzelà–Ascoli Theorem

4 votes
1 answer
987 views

Metric spaces - $(0, 1)$ and $\mathbb{R}$ are not isometric

4 votes
4 answers
1k views

Why is $\mathbb{E}[X] = 1 + \sum^\infty_{k=1}\mathbb{P}(X > k)$ true?

4 votes
1 answer
161 views

What does $f|A$ mean?

3 votes
3 answers
928 views

Understanding this wording of the Schwarz Reflection Principle

3 votes
2 answers
4k views

If $f: X \rightarrow Y$ is continuous, and $X$ is connected, then $f(X)$ is connected

3 votes
2 answers
8k views

Matrix norm inequality proof - does this use Cauchy-Schwarz?

3 votes
4 answers
413 views

Convergence of the integral $\int_0^\infty e^{-x^3} \mathop{\mathrm{d}x}$

3 votes
2 answers
367 views

Separation of $X$ - open and closed subsets

3 votes
1 answer
539 views

If $X$ is a metric, then $X$ is compact if and only if $X$ is sequentially compact - axiom of choice usage

3 votes
1 answer
726 views

Free groups are torsion-free

3 votes
1 answer
237 views

Non-Hausdorff Space With Only One Limit

3 votes
1 answer
155 views

Multiple roots for roots of unity in fields of some characteristic

3 votes
2 answers
7k views

Finding the stable and unstable manifold of this system

2 votes
1 answer
505 views

Prove that if $W \subseteq V$ is a subspace s.t. $W \cap W^\perp = \{0\}$, then $V = W\oplus W^\perp$

2 votes
1 answer
720 views

Deleted comb space proof

2 votes
1 answer
243 views

"The following are equivalent" for only two statements

2 votes
3 answers
1k views

Usage of commas in sets as "such that"

2 votes
2 answers
96 views

Deducing an integer from $0$-$15$ and lying

2 votes
1 answer
133 views

$\omega$-limit set of a point $x \in X$

2 votes
1 answer
223 views

Definition of bounded in a metric space - confirmation

2 votes
1 answer
469 views

Strong Markov Property for Markov Chains - Statement Verification

2 votes
1 answer
2k views

Topology - $f$ is continuous iff $f$ is constant