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Jul
1
answered Power set of $\{\emptyset,\{\emptyset\}\}$
Jul
1
answered Issue with associativity of group
Jul
1
answered Does meet of two partitions of a set always exist?
Jul
1
comment How can you confirm that a problem is open?
Add a "citation needed" to the Wikipedia article and wait ;)
Jul
1
comment G acts freely on X. G is paradoxical implies X is also paradoxical
$\phi$ is bijective
Jun
30
comment Polygons - necessity of checking for collinearity with edge incident to diagonal's vertices?
$v_{i+2}$ could be between $v_i$ and $v_{i+3}$
Jun
30
comment A negative third derivative implies a positive first derivative at a point.
Intuitively, $f'$ must be convex and "on average" equal zero, hence should be negative at the ends and positive "in the middle". In principle "the middle" need not be at $\frac12$ exactly, but the exact computation shows the result anyway
Jun
30
answered Unit group of a field is divisible
Jun
30
comment Can a square be in the form $2x + 1$, when $x$ is odd?
The squere of an even number is $\equiv 0\pmod 4$, the square of an odd number is $\equiv 1\pmod 8$, your $2x+1$ is $\equiv 3\pmod 4$.
Jun
30
comment Showing that infinite product of random variables goes to zero: $\prod^\infty X_i \rightarrow 0 \text{ a.s.}$
Strictly speaking (i.e., of convergence of an infinite product) it is not convergence if the sequence of partial products converges to $0$
Jun
30
comment Does this modulo formula change odds?
No matter what the first four people choose, they just cause a permutation for the final guy's random number,
Jun
30
revised Prove that $\frac{8}{5}\le 2a+b\le 8$
edited tags
Jun
30
comment Equivalence to being a topological group
Your proof of $\implies$ certainly is based on the fact that you can compose $\bar o$ from $o$ and $\operatorname{inv}$. Can you also somehow compose $\operatorname{inv}$ and $o$ from $\bar o$?
Jun
30
answered Why do all steady state probabilities have the same denominator?
Jun
30
answered Is it possible to find the vertices of an equilateral triangle given its center point?
Jun
30
comment What are the most prominent uses of transfinite induction outside of set theory?
Don't you need "merely" a (Hamel) basis of $\mathbb R$ over $\mathbb Q$?
Jun
29
answered Find constant $c < 1$, such that Fibonacci number $F(n) \le 2^{cn}$ for every $n \ge 0$
Jun
29
comment Find constant $c < 1$, such that Fibonacci number $F(n) \le 2^{cn}$ for every $n \ge 0$
Why does "Wikipedia" link to youtube?
Jun
29
comment Principle of Transfinite Induction
In short: In PTI the condition on $P$ says that there cannot be a minimal counterexample. But a nonempty subset of a well-ordered set always has a minimum. Hence the set of counterexamples must be empty, i.e., $P$ holds throughout. - And ordinals are in a way just the standard examples of well-ordered sets
Jun
29
answered Converges to 0 vs. Diverges to 0; Terminology in p-adic Analysis