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Vincent
  • Member for 7 years, 9 months
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5 votes
3 answers
217 views

There is a real number $\xi$ such that one can neither prove nor disprove that $\xi$ is positive

4 votes
1 answer
526 views

Is my proof for Schauder's theorem in non-Banach spaces correct?

4 votes
2 answers
493 views

Counterexample to two-sided limit must equal one sided limits if they exist and are equal

4 votes
1 answer
126 views

Zeros of power series with polynomially bounded integer coefficients

3 votes
2 answers
225 views

A stronger form of Bernoulli's inequality

3 votes
3 answers
139 views

How can $\frac{\mathrm{d}}{\mathrm{d}x}\left[y(u(x))\right] = \frac{\mathrm{d}y}{\mathrm{d}x}$?

3 votes
1 answer
87 views

Why does this limit define a linear map between the tangent spaces?

2 votes
2 answers
262 views

Prove that every rng with a left-side identity has a right-side identity?

2 votes
1 answer
97 views

Do these very weak axioms define a group? (Every element has left identity + left inverse or right identity + right inverse) [duplicate]

1 vote
1 answer
34 views

Are there nontrivial natural number solutions for $\log_{n_1}(m_1) = \log_{n_2}(m_2)$ with $\gcd(n_1, m_1) = \gcd(n_2, m_2) = 1$?

1 vote
1 answer
22 views

Is the best subspace-constrained approximation in $\mathbb{R}^n$ independent of the norm chosen?

0 votes
0 answers
146 views

Why does a subfield of $\mathbb{R}$ not contain every real number?

0 votes
1 answer
51 views

Confusion about convergence in distribution for $X_n \sim U(0, 1/n)$

0 votes
0 answers
79 views

Am I stating the theorem about the dual optimization problem correctly?