Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Users Search
Help Dashboard Sign In Sign Up
Q&A Meta
Q&A
Posts Tags Edits
Ask Question

General Q&A about all branches of theoretical and applied mathematics, including closely-adjacent sciences where the central question is about the math.

367 posts RSS
Activity Age Score Random
Filters (None)
42%
+1 −2
What is the significance of the K-axiom in modal logic S5?

1 answer  ·  posted 9mo ago by Julius H.‭  ·  edited 8mo ago by xamidi‭

modal-logic proof-theory hilbert-systems axioms
54%
+4 −3
Defining Bayes’s theorem from scratch in ZFC

1 answer  ·  posted 10mo ago by Julius H.‭  ·  last activity 8mo ago by xamidi‭

set-theory zfc bayes-theorem
50%
+1 −1
Prove that $\forall x\in\Bbb R:\lfloor x^2\rfloor-\lfloor rx\rfloor\ge-1\iff|r|\le2$.

1 answer  ·  posted 8mo ago by TheCodidacter, or rather ACodidacter‭  ·  last activity 8mo ago by Derek Elkins‭

inequality solution-verification
71%
+3 −0
Using convexity in the proof of Hölder’s inequality

1 answer  ·  posted 10mo ago by Snoopy‭  ·  last activity 8mo ago by Snoopy‭

real-analysis
66%
+2 −0
Does {7,4|3} have a realization on the Klein quartic?

0 answers  ·  posted 8mo ago by WheatWizard‭

polytopes algebraic-geometry
66%
+2 −0
Find length $MP$ in trapezoid

0 answers  ·  posted 8mo ago by TheCodidacter, or rather ACodidacter‭  ·  edited 8mo ago by TheCodidacter, or rather ACodidacter‭

geometry
22%
+0 −5
What are the Peano axioms?

1 answer  ·  posted 9mo ago by Julius H.‭  ·  last activity 9mo ago by rmf‭

logic
66%
+2 −0
The Fourier transform of $1/p^3$

1 answer  ·  posted 9mo ago by C-T‭  ·  last activity 9mo ago by LL 3.14‭

complex-analysis calculus multivariable-calculus integration fourier-analysis
71%
+3 −0
Besov or Triebel-Lizorkin spaces versus Lorentz spaces

0 answers  ·  posted 9mo ago by LL 3.14‭  ·  edited 9mo ago by LL 3.14‭

interpolation Besov-space functional-analysis
28%
+0 −3
What is a “first-order substructural logic that has a cut-free sequent calculus”?

1 answer  ·  posted 9mo ago by Julius H.‭  ·  last activity 9mo ago by Dan Doel‭

logic
40%
+0 −1
What is a one-variable fragment of first-order logic?

0 answers  ·  posted 9mo ago by Julius H.‭

logic
66%
+2 −0
matrix inverse of $I + A$ where $A$ is skew-symmetric

1 answer  ·  posted 9mo ago by Trevor‭  ·  last activity 9mo ago by Trevor‭

linear-algebra
42%
+1 −2
Explain derived categories to someone without a strong background in homological algebra [closed]

0 answers  ·  posted 9mo ago by Julius H.‭  ·  closed 9mo ago by Peter Taylor‭

category-theory
28%
+0 −3
What is a dual object? [closed]

0 answers  ·  posted 9mo ago by Julius H.‭  ·  closed 9mo ago by Peter Taylor‭

category-theory
66%
+4 −1
is arithmetic finitely consistent?

0 answers  ·  posted 9mo ago by Jason‭

proof logic peano-arithmetic incompletness consistency
66%
+2 −0
A program which could derive theorems given formation rules in any modal logic?

1 answer  ·  posted 9mo ago by Julius H.‭  ·  edited 9mo ago by Peter Taylor‭

computational-mathematics proof-assistants
71%
+3 −0
Concrete examples of set theorists thinking independence proofs only determine provability rather than that a statement is neither true nor false?

1 answer  ·  posted 9mo ago by Julius H.‭  ·  last activity 9mo ago by Peter Taylor‭

set-theory
50%
+1 −1
What are the “increasingly stable consequences of the large cardinal hierarchy”?

0 answers  ·  posted 9mo ago by Julius H.‭

set-theory
66%
+2 −0
Fourier transform of an $L^1$ function is uniformly continuous

1 answer  ·  posted 10mo ago by Snoopy‭  ·  edited 10mo ago by Snoopy‭

real-analysis fourier-analysis
37%
+1 −3
Are these introductory logic textbooks wrong to teach ‘unless’ = ‘or’? [duplicate]

0 answers  ·  posted 10mo ago by 8500 Ward‭  ·  closed as duplicate 10mo ago by Peter Taylor‭

logic
66%
+2 −0
For any real number $m$, $ \left|\sum_{n=1}^{\infty}\frac{m}{n^2+m^2}\right|<\frac{\pi}{2} $

1 answer  ·  posted 10mo ago by Snoopy‭  ·  last activity 10mo ago by Snoopy‭

calculus real-analysis
71%
+3 −0
If both $\lim_{x\to\infty}f(x)$ and $\lim_{x\to\infty}f'(x)$ exist, then $\lim_{x\to\infty}f'(x)=0$.

1 answer  ·  posted 10mo ago by Snoopy‭  ·  last activity 10mo ago by Snoopy‭

real-analysis
57%
+2 −1
Strange behavior in elections and pie charts

2 answers  ·  posted 1y ago by TheCodidacter, or rather ACodidacter‭  ·  last activity 10mo ago by Hudjefa‭

probability
66%
+2 −0
$\sup(A\cdot B) = (\sup A)(\sup B)$ where $A$ and $B$ bounded sets of positive real numbers

3 answers  ·  posted 11mo ago by Snoopy‭  ·  edited 11mo ago by Snoopy‭

real-analysis supremum-infimum
60%
+1 −0
Why is $ \int_0^{\infty}\left|\frac{\sin x}{x}\right|\ dx=\infty$?

1 answer  ·  posted 11mo ago by Snoopy‭  ·  last activity 11mo ago by Snoopy‭

real-analysis improper-integral
71%
+3 −0
Is there a $(n_3)$ configuration which is not self-dual?

1 answer  ·  posted 11mo ago by WheatWizard‭  ·  last activity 11mo ago by Peter Taylor‭

combinatorics
25%
+0 −4
Picking 20 different numbers, in the same draw $\;$ vs. $\;$ picking 10 different numbers, in 2 different draws.

1 answer  ·  posted 11mo ago by H7D‭  ·  last activity 11mo ago by Olin Lathrop‭

lottery
66%
+2 −0
Is the nth Betti number determined by orientability?

1 answer  ·  posted 1y ago by WheatWizard‭  ·  edited 12mo ago by WheatWizard‭

betti-numbers algebraic-topology
80%
+6 −0
What is special about the 11-cell and 57-cell?

1 answer  ·  posted 1y ago by WheatWizard‭  ·  last activity 12mo ago by ziggurism‭

polytopes
22%
+0 −5
How can school children intuit why over 100, D is larger? But under 100, D% is larger?

2 answers  ·  posted 1y ago by Chgg Clou‭  ·  last activity 1y ago by Hudjefa‭

high-school-mathematics
75%
+4 −0
Is there a statistical method to identify the type of outliers shown in the pictures attached to my question?

1 answer  ·  posted 1y ago by Ivan Nepomnyashchikh‭  ·  last activity 1y ago by Hudjefa‭

statistics
33%
+0 −2
$\left(\forall \varepsilon >0: |a-b| < \varepsilon\right) \iff a=b$ vs. $\left(\forall \varepsilon > 0: a \le b + \varepsilon \right) \iff a \le b$

1 answer  ·  posted 1y ago by YorkTech‭  ·  edited 1y ago by Peter Taylor‭

inequality
50%
+0 −0
Calculation of limit

0 answers  ·  posted 1y ago by Klein Moretti‭

calculus analysis limits applied-mathematics
25%
+0 −4
How can I improve contrast of red and green, to prove Reverse Triangle Inequality?

1 answer  ·  posted 1y ago by Tortilla‭  ·  last activity 1y ago by Peter Taylor‭

visualization
37%
+1 −3
Solely by eye, how can 16 year olds visually distinguish $\color{red}{\vec{b} - \vec{r}}$ from $\color{limegreen}{|\vec{b}| - |\vec{r}|}$ ?

2 answers  ·  posted 1y ago by Tortilla‭  ·  last activity 1y ago by Olin Lathrop‭

visualization
40%
+0 −1
While pictorializing $|x - y| < |x + y|$, how can 1 picture simultaneously prove (Reverse) △ Inequalities, $|x-y| ≤ |x|+|y|, |x|-|y| ≤ |x-y|$? [duplicate]

0 answers  ·  posted 1y ago by Tortilla‭  ·  closed as duplicate 1y ago by Peter Taylor‭

visualization
75%
+4 −0
Is it possible to show that a normalised random variable has zero mean and unit variance?

0 answers  ·  posted 1y ago by mr Tsjolder‭  ·  edited 1y ago by mr Tsjolder‭

statistics expectation
33%
+1 −4
25% probability that there was a chance of avoiding injury $\quad$ vs. $\quad$ 25% chance of avoiding injury

2 answers  ·  posted 1y ago by DNB‭  ·  last activity 1y ago by Hudjefa‭

probability
81%
+7 −0
How can I choose a point from a uniform distribution within a regular polygon?

2 answers  ·  posted 1y ago by Karl Knechtel‭  ·  last activity 1y ago by trichoplax‭

plane-geometry applied-mathematics sampling
77%
+5 −0
Notation for one-sided hypothesis testing

1 answer  ·  posted 2y ago by tommi‭  ·  last activity 1y ago by Glen_b‭

statistics notation hypothesis-testing
42%
+1 −2
Picture proof for expansion of $x^n−y^n$

2 answers  ·  posted 1y ago by Este‭  ·  last activity 1y ago by Peter Taylor‭

visualization
42%
+1 −2
1 picture proof for the triangle inequality and the reverse triangle inequality

0 answers  ·  posted 1y ago by Este‭  ·  edited 1y ago by trichoplax‭

visualization
71%
+3 −0
Classification for involutory real infinite series

1 answer  ·  posted 1y ago by nsajko‭  ·  last activity 1y ago by Peter Taylor‭

classification real-analysis inverse polynomials series
71%
+3 −0
Is there a quadratic version of exponential smoothing?

0 answers  ·  posted 1y ago by peterbalch‭

statistics signal-processing
55%
+3 −2
Intuitively, why doesn't picking unpopular integers ($> 31$) lower your probability of winning lotteries?

1 answer  ·  posted 1y ago by Ethen‭  ·  last activity 1y ago by Derek Elkins‭

lottery
33%
+1 −4
How to decide whether to buy a lottery with a too negative EV, but passable $\Pr($you win jackpot at least once│n plays)? [closed]

0 answers  ·  posted 1y ago by Chgg Clou‭  ·  edited 1y ago by Chgg Clou‭

lottery
60%
+1 −0
Proving that this relation implies another relation on the Coxeter group [4,3,3,4].

0 answers  ·  posted 1y ago by WheatWizard‭  ·  edited 1y ago by WheatWizard‭

group-theory coxeter-groups
37%
+1 −3
Why do the Expected Values differ, for different wagers of the same lottery?

1 answer  ·  posted 1y ago by Chgg Clou‭  ·  last activity 1y ago by Peter Taylor‭

lottery
80%
+6 −0
Criteria for solvable Minesweeper game?

0 answers  ·  posted 1y ago by Olin Lathrop‭  ·  edited 1y ago by Olin Lathrop‭

algorithm
71%
+3 −0
Properties of distances between adjacent vector elements and related functions

1 answer  ·  posted 1y ago by stofred‭  ·  last activity 1y ago by Artisian‭

analysis vector recreational-mathematics integer-sequences
RSS