Excavator - Badge - Mathematics Stack Exchange

Excavator

Edit first post that was inactive for 6 months.

Awarded 10882 times.

Fine-grained way to measure infinity

Awarded Mar 4 at 5:05

COIsCurious

14510 bronze badges

Definition of self-financing strategy

Awarded Mar 3 at 4:15

Riemann

9094 silver badges20 bronze badges

How do I convince someone that $1+1=2$ may not necessarily be true?

Awarded Mar 2 at 4:25

file

116 bronze badges

Probability of Guessing a Code

Awarded Mar 2 at 4:25

ThankYouForFlyingRyanair

46719 bronze badges

How to show that $\pi \cot \pi \tau = \pi i - 2 \pi i \sum_{m=1}^{\infty} q^m$?

Awarded Mar 2 at 4:25

Kai Wang

8894 silver badges15 bronze badges

Least Square Approximation for Exponential Functions

Awarded Mar 1 at 4:02

David Cherney

34 bronze badges

Evaluating the definite integral $\int_{-\infty}^{+\infty} \mathrm{e}^{-x^2}x^n\,\mathrm{d}x$

Awarded Mar 1 at 4:02

Dqrksun

2,4047 silver badges23 bronze badges

Is there a closed-form equation for $n!$? If not, why not?

Awarded Mar 1 at 4:02

Борат Сагдиев

1857 bronze badges

canonical representation of three skew lines in $\mathbb{P}^3$

Awarded Feb 28 at 9:57

Fnark Man

5432 silver badges13 bronze badges

One thousand exercise in probability third edition section 1.7 question 6

Awarded Feb 28 at 4:09

2rd_7

1595 bronze badges

Intuitive explanation of the singular values

Awarded Feb 28 at 4:09

Huge

1033 bronze badges

The Jacobson radical of polynomial ring

Awarded Feb 26 at 4:32

Narek Bojikian

3892 silver badges15 bronze badges

Solving $ \sqrt{x - 4} + \sqrt{x - 7} = 1 $.

Awarded Feb 26 at 4:32

Evargalo

2,6529 silver badges11 bronze badges

Anti Logarithm Formula

Awarded Feb 26 at 4:32

shrihankp

25810 bronze badges

Pre-Algebra Fractional Exponent Question

Awarded Feb 25 at 18:05

Rishikesh Biswas

5310 bronze badges

A question about divisibility of sum of two consecutive primes

Awarded Feb 25 at 4:35

VizDracViz

1388 bronze badges

Can the product of two Fermat witnesses where the witnesses are prime be a Fermat liar?

Awarded Feb 25 at 4:35

Ryan Pierce Williams

5334 silver badges13 bronze badges

finding the formula for the arc length of any curve problems with the dx

Awarded Feb 24 at 19:37

FishDrowned

1,0293 silver badges19 bronze badges

Why is "convexity" important in mathematics?

Awarded Feb 24 at 4:04

mirh

1033 bronze badges

Prove that $(x+y+z)^2(yz+zx+xy)^2 \leq 3(y^2+yz+z^2)(z^2+zx+x^2)(x^2+xy+y^2)$

Awarded Feb 23 at 4:23

Joyneel Bepari

1,1753 silver badges14 bronze badges

Poisson Distribution Problem relating to birthdays

Awarded Feb 23 at 4:23

Tefo

1158 bronze badges

Prove rayleigh quotient = operator norm without referring to eigenvalues

Awarded Feb 23 at 1:56

Corentin Bodart

1284 bronze badges

Combinatorics: How many ways can an $m \times n$ board be traversed from the top left to the bottom right by moving only to the right and down?

Awarded Feb 22 at 4:07

SquareFinder

1033 bronze badges

Showing that something is a Pushout

Awarded Feb 22 at 4:07

Antonio

1651 silver badge8 bronze badges

Sets with same members are member of same sets? Seeking deeper insights on link between extensionality and set equality, with or without FOL equality.

Awarded Feb 22 at 4:07

gavenkoa

5655 silver badges9 bronze badges

A generalization of center of a ring

Awarded Feb 21 at 4:52

Maths is everywhere

568 bronze badges

What does it mean when two sets are "adjoined" in a metric space?

Awarded Feb 20 at 4:10

garou

32 bronze badges

J. J. Rotman's proof that the cone is contractible

Awarded Feb 20 at 4:10

Mark S

337 bronze badges

A subset of the set of vertices of a simple graph with an even/odd property

Awarded Feb 19 at 5:55

Euclid

1,9453 silver badges21 bronze badges

Genus of a Curve - Riemann-Roch

Awarded Feb 19 at 5:55

WillO

3,22722 silver badges26 bronze badges

When is $(6a + b)(a + 6b)$ a power of 2?

Awarded Feb 19 at 5:55

Twineee The Pickle Wizard

53 bronze badges

Complexity/Operation count for the forward and backward substitution in the LU decomposition?

Awarded Feb 18 at 4:20

DanielTuzes

1034 bronze badges

Coupon Collector's problem, version with multiple coupons in a box

Awarded Feb 18 at 4:20

bettersayhello

19910 bronze badges

Localization of the Integer Ring

Awarded Feb 18 at 4:20

Alon Amit

32 bronze badges

Shorter notation for sine function

Awarded Feb 18 at 4:20

nav

53 bronze badges

How to find $\int_{0}^{\pi/2} \log ({1+\cos x}) dx$ using real-variable methods?

Awarded Feb 18 at 4:20

Kirusanth

6465 silver badges12 bronze badges

Convergence in Skorokhod topology implies convergence in $L^1$.

Awarded Feb 18 at 4:20

George

2761 silver badge8 bronze badges

Is every open set a disjoint union of open balls?

Awarded Feb 18 at 4:20

Daniel Tinoco

738 bronze badges

Unbiased estimator of a uniform distribution

Awarded Feb 17 at 17:51

Mewbacca

536 bronze badges

Floor function in complex plane [closed]

Awarded Feb 17 at 6:21

Martin Mächler

1135 bronze badges

Elementwise vs componentwise vs coordinatewise vs pointwise

Awarded Feb 16 at 5:19

魔大农

33 bronze badges

Misunderstanding in the universal property of the Cartesian product

Awarded Feb 16 at 5:19

Hug de Roda

4,0601 gold badge6 silver badges20 bronze badges

Find the sum of $\sum \frac{1}{k^2 - a^2}$ when $0<a<1$

Awarded Feb 15 at 5:40

Ruchin Himasha

4911 silver badge11 bronze badges

Virtual dimension and index?

Awarded Feb 14 at 4:39

El Rafu

6603 silver badges12 bronze badges

Partial fractions for $\pi \cot(\pi z)$

Awarded Feb 13 at 4:07

Jihai Zhu

32 bronze badges

Sheaf of differetials on $\mathbb{P}^n_A$

Awarded Feb 13 at 4:07

Lucas Henrique

2,81113 silver badges24 bronze badges

Prove $\sqrt{\frac{a+4bc}{4a+bc}}+\sqrt{\frac{b+4ca}{4b+ac}}+\sqrt{\frac{c+4ab}{4c+ab}}\ge 3,$ when $a+b+c=3.$

Awarded Feb 12 at 6:04

Yusuf Waleed

46214 bronze badges

Basis of Clifford algebra

Awarded Feb 12 at 6:04

Nicholas Todoroff

9,7141 gold badge6 silver badges28 bronze badges

Prove that $\det(xI_m-AB)=x^{m-n}\det(xI_n-BA)$

Awarded Feb 12 at 6:04

Asigan

2,3611 gold badge5 silver badges20 bronze badges

Combination problem with constraints

Awarded Feb 12 at 6:04

Mohsenasm

1033 bronze badges

A table of homology and cohomology groups

Awarded Feb 12 at 0:27

Iirne

52 bronze badges

Why does $\gcd\left(\frac{n_1}{d}, \frac{q}{d}\right) = 1$ imply that $\sum \varphi\left(\frac{q}{d}\right) = q$?

Awarded Feb 11 at 5:01

Sokoban

2259 bronze badges

How to prove an Inequality

Awarded Feb 11 at 5:01

Damián Gil

33 bronze badges

Are all definite integrals calculable by method of Riemann sums?

Awarded Feb 11 at 5:01

Anshul Prajapati

52 bronze badges

Can an Euler path of a complete directed graph be partitioned into Hamilton paths?

Awarded Feb 11 at 5:01

Zoe Allen

7,86112 silver badges42 bronze badges

Existence and Uniqueness Theorems: When to use Picard-Lindelöf, Lipschitz, etc.

Awarded Feb 11 at 5:01

genepeer

1,70011 silver badges29 bronze badges

Collections of the sum of two uniformly-integrable families are still uniformly integrable [closed]

Awarded Feb 11 at 5:01

Tom Zhou

32 bronze badges

Is there any modular arithmetic property relating $\mod mn$ to $\mod m$?

Awarded Feb 11 at 5:01

rahul

32 bronze badges

Divisibility Rules of 2019

Awarded Feb 11 at 5:01

Ronchen Luo

1056 bronze badges

Continuous mapping on a compact metric space is uniformly continuous

Awarded Feb 11 at 5:01

user1550110

551 silver badge5 bronze badges

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