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Dustan Levenstein
  • Member for 10 years, 7 months
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55 votes

What are some conceptualizations that work in mathematics but are not strictly true?

38 votes
Accepted

Why can't we use implication for the existential quantifier?

26 votes

Why can't Russell's Paradox be solved with references to sets instead of containment?

24 votes
Accepted

The number of elements which are squares in a finite field.

23 votes
Accepted

Why is the Axiom of Choice not needed when the collection of sets is finite?

19 votes

Limit of $\arctan(x)/x$ as $x$ approaches $0$?

18 votes
Accepted

Interesting Property of Numbers in English

15 votes
Accepted

In Cantor's Diagonalization Argument, why are you allowed to assume you have a bijection from naturals to rationals but not from naturals to reals?

14 votes

Why can't I simply use algebra to solve this inequality?

13 votes
Accepted

Why $x<\tan{x}$ while $0<x<\frac{\pi}{2}$?

12 votes
Accepted

Do these theorems about power sets hold for the empty set?

12 votes
Accepted

Let $f:(\mathbb{R}\setminus\mathbb{Q})\cap [0,1]\to \mathbb{Q}\cap [0,1]$. Prove there exists a continuous$f$.

10 votes
Accepted

When does $x^{n}=y^{n}$ imply $x=y$.

9 votes

Is a topological space isomorphic to some group?

9 votes
Accepted

If $E/F$ is algebraic and every $f\in F[X]$ has a root in $E$, why is $E$ algebraically closed?

9 votes

Is there a way to solve $\sqrt a + \sqrt b = \sqrt n$ analytically?

8 votes
Accepted

How fundamental is Euler's identity, really?

8 votes

What's wrong with this transformation?

7 votes
Accepted

Proving a property of transposition

7 votes

Pi in combinatorial game theory

7 votes
Accepted

For a commutative ring R without identity, there exists a∈R such that Ra≠R

7 votes
Accepted

Evaluating $0^0$ and its limit

7 votes
Accepted

Matrix - Show $\det(A) =0$

6 votes

Finding a choice function without the choice axiom

6 votes

Proof of Existence of Algebraic Closure: Too simple to be true?

6 votes
Accepted

Is my intuition of "If $p \mid ab$ then $p \mid a$ or $p \mid b$" correct?

6 votes
Accepted

Problems on Sylow Theorems

6 votes
Accepted

Are there homomorphisms of group algebras that don't come from a group homomorphism?

6 votes

geometric methods in number theory

6 votes
Accepted

Short exact sequence of $\mathbb{R}[X]$-modules that does not split

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