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David Reed
  • Member for 5 years, 3 months
  • Last seen this week
  • L.A./Dallas
17 votes
Accepted

Zolotarev's Lemma and Quadratic Reciprocity

11 votes
Accepted

Defining $e^{i \theta}$

9 votes
Accepted

What is the benefit in constructing the integers from natural numbers?

9 votes

What is the significance of deciding the convention of $1 \text{ radian} = 180 \text{ degrees}$ over $\pi$?

8 votes

Easy proof of the irrationality of $e$

8 votes

How do I study Stein & Shakarchi's Complex Analysis

6 votes

Why is the fact that a quotient group is a group relevant?

6 votes

Proof that vector space $C([a,b])$ of all functions from $[a,b]\to \mathbb{R}$ is infinite dimensional?

5 votes

How to differentiate a power series?

5 votes
Accepted

How can two elements of group $S_4$ generate the whole group $S_4$?

5 votes

How to prove Euler's formula: $e^{i\varphi}=\cos(\varphi) +i\sin(\varphi)$?

5 votes

Statement and proof of the sequential characterization of limits

4 votes
Accepted

Logical Connectives and Quantifiers

4 votes

Axiomatic set theory book recommendation

4 votes
Accepted

Abstract Algebra Preparation

3 votes

Is $\mathbb R^n$ its own boundary?

3 votes

Proving limits using $\epsilon-\delta$ definition

3 votes

Prove that for every $n$ it is possible to find $n$ consecutive positive numbers that are not prime

3 votes
Accepted

Limit of $1/k$ and the $p$-series test

3 votes

Why can the limit be moved inside the logarithm in $2 \lim_{x \to 0} \left[ \ln \frac{\sin x}{x} \right]$?

3 votes

Bohr Radius of an atom

3 votes

Use Frobenius' method to find two independent solutions to the ODE $4tx''(t)+2x'(t)+x(t)=0$

2 votes

Most gentle introduction to undergraduate analysis

2 votes
Accepted

Gradient of $f$ at $x$ is perpendicular to level sets $N_y$ of $f$.

2 votes
Accepted

Can one apply LHopitals' rule to differentiable functions defined over the naturals?

2 votes
Accepted

How to go from $dx = -t^2dt$ to $\frac{d}{dx} = -t^2\frac{d}{dt}$

2 votes

Find cdf given pmf

2 votes
Accepted

Dominated convergence theorem with supremum and finite measure?

2 votes

Basis of the image of the product of two matrices

2 votes

What are good mathematical heuristics for choosing a good target function that always produce a stable linear regression solution?