B.D

2,101 reputation

320

bio	website
	location	New York
	age	27
visits	member for	9 months
	seen	yesterday
stats	profile views	400

Defected from pure mathematics to mathematics education, but am convinced each needs the other (and more than either would admit).

	2,101 reputation	bio	website		visits	member for	9 months
320 badges		location	New York		seen	yesterday

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12 Questions

views newest activity votes

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Probability that a stick randomly broken in five places can form a tetrahedron

apr 24 at 23:54 leonbloy 12.1k

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answer

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Imperfect digit-to-digit invariants in Base $10$

number-theory elementary-number-theory problem-solving exponentiation

mar 15 at 5:41 Erick Wong 6,329

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answers

115

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Forcing Question about a sequence of functions from $\aleph_{0}$ into $2 = \{0, 1\}$

set-theory cardinals model-theory axioms forcing

feb 26 at 18:51 B.D 2,101

votes

answers

430

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Arc sums for a circle of $k$ positive integers whose total sum is $n$

combinatorics recreational-mathematics problem-solving pigeonhole-principle

jan 29 at 5:51 B.D 2,101

votes

answers

264

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Literature on Mathematical Problem Posing

reference-request recreational-mathematics problem-solving

jan 27 at 23:09 B.D 2,101

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answer

178

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Origin and use of an identity of formal power series: $\det(1 - \psi T) = \exp \left(-\sum_{s=1}^{\infty} \text{Tr}(\psi^{s})T^{s}/s\right)$

linear-algebra number-theory power-series determinant p-adic-number-theory

jan 19 at 18:46 B.D 2,101

votes

answers

390

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Evaluating $\int_{0}^{x} e^t \sqrt{2 + \sin(2t)} \, dt$

calculus integration derivatives problem-solving

nov 21 at 2:02 B.D 2,101

votes

answers

219

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Mean and Median in a Classic River Crossing Problem

combinatorics statistics recreational-mathematics problem-solving integer-programming

nov 9 at 21:18 joriki 92.1k

votes

answer

432

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Recovering a finite group's structure from the order of its elements.

abstract-algebra group-theory finite-groups abelian-groups computational-algebra

nov 4 at 16:53 Alexander Gruber 15.1k

vote

answer

234

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Multiplication Table with a frame and picture of equal sum

elementary-number-theory arithmetic recreational-mathematics contest-math problem-solving

nov 4 at 0:14 B.D 2,101

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132

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Adapting a proof on elements of order 2: from finite groups to infinite groups

abstract-algebra group-theory finite-groups proof-strategy

oct 27 at 18:27 Steve D 5,235

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answer

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Generalization of groups of the form (R-{0}, regular multiplication)

abstract-algebra group-theory reference-request

sep 28 at 6:02 B.D 2,101