CURED - 2020-06-25

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rschwieb

02:19

Software support math.stackexchange.com/q/3733406/29335

SmokeDetector

[ SmokeDetector | MS ] Link at beginning of body (42): Show that the p∧q → q is a tautology without using a truth table ✏️ by Fatima Ibrahim on math.SE

Harish Chandra Rajpoot

03:10

Consider closure C1 C2

Harish Chandra Rajpoot

03:38

@amWhy That's really helpful for me. Thanks

8 hours later…

Saad

11:14

For closure:

Q: A combinatorics puzzle

Eight students are entered in a math competition. They all have to solve the same set of 8 problems. After correction, we see that each problem was correctly resolved by exactly 5 students. Show that there are two students who together have solved all the problems.

combinatorics

Q: Steiner triple systems

Prove directly that if an STS(v) and STS(w) exist, then an STS(vw) exists. I don't how to show it directly but i can show it with theorems

combinatorics discrete-mathematics

For deletion:

-1

Q: Use induction to prove that for every integer $n ≥ 0$, $5^{n+2} + 6^{2n+1}$ is divisible by $31$.

Use induction to prove that for every integer $n ≥ 0$, $5^{n+2} + 6^{2n+1}$ is divisible by $31$.

elementary-number-theory discrete-mathematics induction divisibility

Martin R

12:07

Bad answer: math.stackexchange.com/a/3731594/42969 – Copy/paste from CAS program without any explanation, and not even what OP is looking for.

Saad

12:26

A: Prove that $f_{2k} \cdot f_{(2k+2)} + 1$ is a perfect square, where $f_n$ is the $n$th Fibonacci number, $n\geq0$.

Hint: it's not just any perfect square, it's the square of a certain Fibonacci number.

A one-line “hint” with 3 up votes to a PSQ.

amWhy

12:54

@MartinR Looks like they've been suspended again, this time for a year, for low-quality contributions.

amWhy

13:09

@MartinR Oh, and the answer has been deleted.

rschwieb

13:22

@amWhy Nice! Glad to see that eventually happens.

This seems like it needs to be deleted whenever possible: math.stackexchange.com/q/3734087/29335

amWhy

@rschwieb Open for deletion!

rschwieb

@amWhy And now gone.. thanks

amWhy

@rschwieb Glad to help get rid of it!

rschwieb

13:42

This seems like the third PSQ in a VERY short time interval by a 1 rep indian username: math.stackexchange.com/q/3734120/29335 Something feels automated about it

amWhy

@rschwieb They, or users, have since deleted two of the questions. Maybe worth a flag if they continue.

rschwieb

If I could demonstrate the pattern, I would, but at the moment it's just anecdotal :/

amWhy

@rschwieb I get it. At least you've alerted users to this username, and a very poor post. That's a great start.

rschwieb

14:07

They subsequently edited the title to "prove or disprove" from an already pretty good title. Cute.

amWhy

14:18

@rschwieb Almost gone: one more delete vote needed here.

rschwieb

second strike math.stackexchange.com/q/3734149/29335 for that particular username in an hour

RRL

14:44

DA, DB, DC, DD, DE, DF, DG, DH

DI, DJ, DK, DL

amWhy

15:04

@rschwieb See also this answer?

rschwieb

15:14

@amWhy 🤮

At times like this I feel we need a computer virus that can climb onto a machine, and simulate all interactions with a site in the outside world for that machine's user. That way they can continue to troll to their heart's desire and be oblivious that they are not actually doing the damage they thought they were.

amWhy

@RRL All gone!

@rschwieb Hah! Indeed!

user21820

16:01

D1, D2, D3.

D4, D5, D6.

D7, D8, D9.

D10, D11, D12.

rschwieb

16:27

Psq math.stackexchange.com/q/3734278/29335

2 hours later…

sai-kartik

18:18

PSQ

-4

Q: I am unable to solve the following integral

Help me solve this integral $$\int e^{|x|}cos(nx)dx$$

calculus integration

Has an answer btw^

and an upvote for some reason 🤔

rschwieb

19:15

and again: math.stackexchange.com/q/3734516/29335 looks like DietrichBurde is onto them too

@sai-kartik Deleted now, it looks like.

amWhy

@rschwieb Open for deletion.

Matt Samuel

19:39

I accidentally reopened it.

amWhy

@MattSamuel Which question?

Matt Samuel

-4

Q: prime and maximal ideals of the matrix ring

Let $F$ is a field and $R=\bigg\{\begin{pmatrix}a&b\\0&c\end{pmatrix}|a,b,c \in F\bigg\}$.Find all the prime and maximal ideals of the R matrix ring.

abstract-algebra ring-theory

I closed it again as a duplicate of the wrong question too.

Looks like it was deleted.

amWhy

20:23

@MattSamuel You can edit which questions you'd like to add or delete as duplicate targets.

Matt Samuel

@amWhy I forgot about that. Until very recently I was exclusively using the android app where such things are not possible.

rschwieb

More of the same...math.stackexchange.com/questions/3734596/…

amWhy

@MattSamuel No problem!

@rschwieb I've downvoted, voted to close, and flagged for mod attention with links to previous duplicate, though deleted, posts.

The more flags for mod attention, the better.

rschwieb

Is it like this all the time, just not in my tags?

amWhy

@rschwieb Today is particularly problematic in this tag. Not every day in this tag. But yes, this is a common phenomenon across tags. Which it why it helps to have users here who follow diverse tags.

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