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B.Swan
  • Member for 7 years, 5 months
  • Last seen more than a week ago
59 votes
6 answers
15k views

Exam with $12$ yes/no questions (half yes, half no) and $8$ correct needed to pass, is it better to answer randomly or answer exactly 6 times yes?

9 votes
3 answers
3k views

Avoiding numerical cancellation question for $\sin x -\sin y$ for $x \approx y$

9 votes
0 answers
263 views

Method of showing maximal number of intermediate field extensions of a Galois extension with given degree

6 votes
1 answer
86 views

One room for rent, select reservations to minimise unrented days.

4 votes
2 answers
77 views

$f: \mathbb{R} \rightarrow \mathbb{R}, f(0)=1, f(x+y) \leq f(x)f(y)$. Show that if $f$ continuous in $x=0$, $f$ is continuous in $\mathbb{R}$.

4 votes
1 answer
425 views

Why does $G$ need to be finite in this proof of a normal subgroup $N$ containing all elements of order coprime to $[G:N]$?

4 votes
0 answers
198 views

Maximizing chance that randomly drawn numbers fill a row or column

4 votes
1 answer
615 views

Fundamental group of $S^n \setminus S^m$

4 votes
1 answer
75 views

How to set boundaries when approximating a discrete RV with a normally distributed RV?

3 votes
0 answers
55 views

Is there an efficient algorithm for generating square matrices up to having same rows and colums

3 votes
1 answer
79 views

How does $X^2+1 \in \Bbb{F}_2(T)[X]$ have infinitely many roots in the ring of dual numbers over $\Bbb{F}_2(T)$?

3 votes
3 answers
79 views

Is there a metric space such that for a sequence of nonempty subsets $K_1 \supset K_2 ....$ the intersection of all subsets is empty?

3 votes
0 answers
263 views

What matrices fulfill trace$(A^2)=0$?

3 votes
1 answer
75 views

Integrating over integral limits

3 votes
3 answers
1k views

What is the difference between a definition and a characterization?

3 votes
1 answer
117 views

Question regarding classification of subspace configurations up to isomorphism and classifying orbits

3 votes
1 answer
210 views

Representative system of congruence classes in $\mathbb{Q}$

3 votes
2 answers
794 views

Dimensions of image and kernel of a $n \times n$ matrix

2 votes
1 answer
472 views

Number of elements in equivalence classes of factor groups and sets

2 votes
1 answer
109 views

Statements about linear equation systems

2 votes
2 answers
110 views

Determining whether $\int_{0}^{\infty} \frac{x \sin(x)}{1+x^2}dx$ converges and converges absolutely

2 votes
2 answers
245 views

Proving that a function is not totally differentiable in $(0,0)$ [duplicate]

2 votes
1 answer
727 views

Proving that every Hölder-continuous function with an exponent $\alpha>1$ is constant. [duplicate]

2 votes
0 answers
40 views

Canonical transformations to quotient spaces

2 votes
1 answer
875 views

Question regarding bipartite graphs and their subgraphs.

2 votes
1 answer
95 views

How does one justify $\limsup\limits_{n\rightarrow \infty} a_n=\limsup\limits_{n\rightarrow \infty} a_{n+1}$?

2 votes
3 answers
3k views

Proving $ \sum_{n=1}^{\infty} nz^{n} = \frac{z}{(1-z)^2}$ for $z \in (-1, 1)$ [duplicate]

2 votes
1 answer
43 views

When is $p_1 \times p_2: V\rightarrow V/U_1 \oplus V/U_2, v\longmapsto (p_1(v),p_2(v))$ surjective?

2 votes
1 answer
3k views

Proving the existence of a complement subspace $U' \subset V$.

2 votes
1 answer
80 views

Fixed point of a map iteration sequence