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Joseph Martin's user avatar
Joseph Martin's user avatar
Joseph Martin's user avatar
Joseph Martin
  • Member for 9 years, 5 months
  • Last seen more than a month ago
4 votes
Accepted

Inequality involving inner product and norm

3 votes

Using Gauss elimination to check for linear dependence

3 votes
Accepted

Find at least $5$ integers $n$ such that $\varphi(n)=16$

3 votes
Accepted

Definition of unitor in monoidal category

3 votes
Accepted

Number of $\pm 1$ matrices whose determinant is negative or zero

2 votes
Accepted

Proving that a function is not injective.

2 votes
Accepted

Is this valid notation?

2 votes

integration $\int_{0}^{1/8} \frac{4}{\sqrt{(1-4x^2)}} \,dx$

2 votes

Proof of $\pi_1(S^n)=0$ if $n \geq 2$.

2 votes
Accepted

Regarding the pointwise left adjoint of the $\mathrm{Hom}_*$ functor for cartesian closed categories

2 votes

Does $R\cong S$ imply $R[X] \cong S[X]$?

2 votes
Accepted

$a,b \in \mathbb Z$ we have that $a+ b\phi \in \mathbb Z[\phi]^* \iff a^2 +ab-b^2 = \pm 1$

1 vote

Why is operator norm defined the way it is?

1 vote
Accepted

Finding conditional expectation for 3 tosses of a coin.

1 vote

Can natural transformations be viewed as functors between images of functors?

1 vote

Bound on the number of people having meetings with each other

1 vote

How many arrangements of six books where two blue books must be next to each other?

1 vote

How to calculate weighted average with a zero?

0 votes

1 in 4, two chances, only one needs to hit

0 votes

How to find the range of a composite function?

0 votes

How to prove that $\left(\ln(\ln(x)) \right)^2 \lt \ln(x)$

0 votes
Accepted

Complex SUVAT help?

0 votes

Splitting Fields over arbitrary fields

0 votes
Accepted

Name of a limit theorem

0 votes

How to find the basis of the following vector space?

0 votes

$Ax=0$, $x \neq 0$ implies $A$ is singular

0 votes
Accepted

How to prove an expression to be a tensor?

0 votes

Why is $S^1\times \{1\}$ homotopy equivalent to the solid torus $T^2 = D^2 \times S^1$? (see attached picture)

0 votes

How would Jack allocate his time to maximize his pleasure?

0 votes

If $A$ and $B$ are invertible matrices, is $A+B$ also an invertible matrix?