/sci/ - Science & Math

34KiB, 660x473, 1614188138041.png

View Same Google iqdb SauceNAO

Anonymous Sat 19 Feb 02:52:14 2022 No.14244657 View Reply Original Report

Quoted By: >>14247715

>Have something to prove
>Decide to use induction
>Assume that for an arbitrary number a proposition is correct
>Use the starting proposition to prove stuff
>Literally I assumed something is true to prove other stuff is true
>Thus conclude that this is true for every number greater than the starting one
why is this allowed?

It's like building a house on sand and expecting it to hold, it just makes no sense, there is no point in using it because you assume something is true and then extend it to everything..

29 posts and 2 images omitted

Anonymous

Anonymous Sat 19 Feb 2022 23:47:59 No.14247715 Report

Quoted By:

>>14244657
>>14244670
>>14244677
>>14244741
>>14245923

Let's rephrase this, so that retarded OP can undertand it. Induction is typically used for proofs over the natural numbers. We use the well ordering of the natural numbers to prove whatever we want to prove. The natural numbers are constructed using the peano axioms. We use the "axiom of induction" for our proof. First, we make sure our problem works for out first case, the base case. Then we show, that if our theorem holds for n it also holds for n+1. So we just ASSUME it works for n. But because we checked the base case, this implies should the base case be true, that it also holds for the successor of the base case and since this is true, the successor of this is true as well. Thus, we showed it's true for all n greater or eaqul to the base case

Anonymous

Anonymous Sun 20 Feb 2022 01:45:26 No.14248059 Report

Quoted By:

>>14245942
I think an issue is you are asking for a counterexample
when what is required is to somehow prove that there are not inputs for which induction fails for e.g. technical reasons like dividing by zero (or other more esoteric technical reasons).

Anonymous

Anonymous Sun 20 Feb 2022 03:25:30 No.14248249 Report

Quoted By: >>14248447

>>14245177
but isn't "it doesn't work for 50" a contradiction for "if it works for x, it works for x+1" because it works for 49, and 50 is 49+1? The conclusion that "if it works for x, it works for x+1" must have been a mistake, even if a small one.

Anonymous

Anonymous Sun 20 Feb 2022 05:03:41 No.14248447 Report

Quoted By:

>>14248249
precisely. anon is very dense and this part isn't clicking for some reason.

Anonymous

Anonymous Sun 20 Feb 2022 14:04:35 No.14249291 Report

Quoted By:

>>14245682
Let's go with the following example:
$\mathbb{Q}={\frac{z}{n} | z\in\mathbb{Z}, n\in\mathbb{N}}$
For clarification, $0\not{\in}\mathbb{N}$ .
The statement we want to prove or disprove is $\forall n \in \mathbb{N} \Rightarrow \frac{1}{80-n} \in \mathbb{Q}$

Of course we know that for n=80 the undefined value won't be in $\mathbb{Q}$ , but let's try to "prove" it with induction.

>Base:
for n=1 we know that $\frac{1}{80-1}=\frac{1}{79}\in\mathbb{Q}$
So we've proven the base case to be true.

>Step:
Let's assume the statement is true for n.
That is, $\frac{1}{80-n}\in\mathbb{Q}$
Let's show that from that follows that $\frac{1}{80-n-1}\in\mathbb{Q}$
$(80-(n+1)=80-n-1)$

To show that $\frac{z}{n}$ is in $\mathbb{Q}$ we need to show that $(z\in\mathbb{Z})\wedge(n\in\mathbb{N})$ .
We know that $1\in\mathbb{Z}$ , so now we need to show that if $(80-n)\in\mathbb{N}$ for a given n than it follows that $(80-n-1)\in\mathbb{N}$ .

$80-n\in\mathbb{N} \rightarrow 80-n\geq1 \rightarrow 79\geq n$
So if $(80-n)\in\mathbb{N}$ it follows that $79\geq n$ .

If I were thorough I'd also show that this statement is true for n>80 as well, but I'm lazy and running out of characters.
In retrospect I should have shown that { $\frac{z}{n} | n\in\mathbb{N}, z\in\mathbb{Z}$ } = { $\frac{z}{n} | z\in\mathbb{Z}, n\in\mathbb{Z}\setminus(0)$ }, but fuck it, let's pretend I did.

So we know this statement is true when $79\geq n$ or $n>81$ , let's assign n=79.
for n=79 we see that $80-79=1\in\mathbb{Z}\setminus (0)$ and therefor $\frac{1}{80-79}\in\mathbb{Q}$ .
However, $80-(79+1)=80-80=0 \not{\in}\mathbb{Z}\setminus 0$ , and therefor $\frac{1}{80-80} \not{\in} \mathbb{Q}$

And indeed we've shown a contradiction.

53KiB, 880x480, cheesed-.jpg

View Same Google iqdb SauceNAO

Anonymous Sun 20 Feb 13:38:32 2022 No.14249225 View Reply Original Report

Quoted By: >>14249234

Anyone ever had sexual headaches? Occurs even after masturbation. I've never met another person who's experienced this and it hurts so bad everytime there's a resurgence.

https://en.m.wikipedia.org/wiki/Sexual_headache

349KiB, 1080x1350, miley_cyrus1 (10).jpg

View Same Google iqdb SauceNAO

Anonymous Sun 20 Feb 01:38:40 2022 No.14248042 View Reply Original Report

Quoted By: >>14248175 >>14249236

Would a combination of satellite imagery capable of detecting radiation and lasers mounted to said satellites be able to blow up a missile as it takes off on earth in the future? Like would it be feasible to create a system like that?

All this stuff with Ukraine has me wondering if there would ever be a system that would render nuclear missiles pointless because everyone would know that we could blow them up as soon as they left their silo, thereby causing catastrophic damage in the home country or minimal damage over the ocean.

Pic related is a scientist, I think.

4 posts and 1 image omitted

Anonymous

Anonymous Sun 20 Feb 2022 01:52:00 No.14248066 Report

Quoted By:

>>14248047
>>14248051
>>14248060
BASED COOMPOSTERS

thread theme
https://youtu.be/cg4Ceo8tVu8

Anonymous

View Same Google iqdb SauceNAO mileyy.jpg, 796KiB, 1000x1500

Anonymous Sun 20 Feb 2022 02:31:33 No.14248154 Report

Quoted By: >>14248165

>>14248056
I've been trying to read your post but always get distracted

Anonymous

Anonymous Sun 20 Feb 2022 02:36:25 No.14248165 Report

Quoted By:

>>14248154
She is incredibly sexy and an ultimate scumbag at the same time. Brain is confused

Anonymous

View Same Google iqdb SauceNAO R (29).jpg, 274KiB, 1185x1007

Anonymous Sun 20 Feb 2022 02:42:36 No.14248175 Report

Quoted By:

>>14248042
Such a system was studied repeatedly by the US under the aptly named Star Wars program of the late 1980s.

Result:
>too expensive
>USSR collapsed anyways
>project shelved

The two main methods studied were "Brilliant pebbles" (small satellites that would detect and ram missiles during boost phase in LEO) and giant nuclear-powered space lasers (which failed in testing).

SpaceX's Starship would likely enable a lower cost version of Brilliant Pebbles to be deployed if the DoD so desires.

Anonymous

Anonymous Sun 20 Feb 2022 13:44:01 No.14249236 Report

Quoted By:

>>14248042
>satellite imagery capable of detecting radiation
if you mean THE radiation, as in the plutionium in the warheads, you are out of your fucking mind
if you mean infrared flash from rocket launches, that's tech we've had and used for decades
>blow up a missile as it takes off on earth
no
anything like that would have to be right on top of it as it takes off and shooting down satellites is trivial
in the event of ICBM's flying nobody would give one Sunday morning fuck about creating space garbage

165KiB, 860x625, pf.jpg

View Same Google iqdb SauceNAO

Anonymous Sat 19 Feb 18:55:39 2022 No.14246537 View Reply Original Report

Quoted By: >>14247812 >>14247987

The covid crisis has already ended, Pfizer's Paxlovid pill decreases symptoms by 90%, combined with vaccine even, that is more than enough so nobody will ever die of Covid again.

Except... there is """"""""""""""""""'not enough supply of it""""""""""""""""""'. In a nutshell, for those of you that don't get finance:

>Ok, whole world got their 2nd shot. Let's sell our pills now for money
>Wait.. media, governments, everyone started talking about "booster shots"
>Oh noo guise, we can't produce enough paxlovid yet, but we can produce enough vaccines as much as you want to buy heheh.. after all, everyone needs to get vaccinated, while paxlovid is only for people who show symptons (a vast minority)

How do we profit from this?

3 posts omitted

Frenanon

View Same Google iqdb SauceNAO 1645237406091.jpg, 4MiB, 5248x3500

Frenanon Sun 20 Feb 2022 00:16:15 No.14247812 Report

Quoted By: >>14247878

>>14246537
Did you guys not hear? Trudeua called in mercenaries to attack Peaceful Protestors. People died today. Every country around the world is criticizing Trudeua, saying this Covid thing has gone on long enough, and people are quite upset.
The WEF got called out in Canada Parliament recently, and they had to cut the mic.

Making a "profit" off this is probably the last thing you should be concerned about right now. Any medfags familiar with the Nuremburg Trials?

They are DESPERATELY trying to stir up a war in Ukraine right now (btw, Putin has stated multiple times he is NOT invading, and he is kind of pissed off at Western Media for trying to Warmonger people into WWIII).

>>>/pol/362002221
>>>/pol/362014420

Anonymous

View Same Google iqdb SauceNAO Fake News.jpg, 132KiB, 800x573

Anonymous Sun 20 Feb 2022 00:38:19 No.14247878 Report

Quoted By:

>>14247812

Viruses don't exist

Viruses don't exist Sun 20 Feb 2022 01:12:53 No.14247987 Report

Quoted By: >>14248125

>>14246537
there's no covid, shill.

Anonymous

Anonymous Sun 20 Feb 2022 02:15:24 No.14248125 Report

Quoted By: >>14249058

>>14247987
yes there is and it came from the US
https://imgur.com/a/CRwan3n

Viruses don't exist

Viruses don't exist Sun 20 Feb 2022 11:54:07 No.14249058 Report

Quoted By:

>>14248125
no, faggot, there's no covid. the word "covid" did come from US, of course.

79KiB, 600x600, 1532336707249.jpg

View Same Google iqdb SauceNAO

Anonymous Sat 19 Feb 16:13:48 2022 No.14246110 View Reply Original Report

Quoted By:

Whats the science behind cute animals?

28 posts and 8 images omitted

Anonymous

Anonymous Sun 20 Feb 2022 07:01:42 No.14248598 Report

Quoted By: >>14248619

>>14246180
Based otters btfo'ing the fat amerimutt

Anonymous

Anonymous Sun 20 Feb 2022 07:02:44 No.14248600 Report

Quoted By:

They are furry which hide their hideous features and have big eyes.

Anonymous

Anonymous Sun 20 Feb 2022 07:10:50 No.14248619 Report

Quoted By: >>14248856

>>14248598
>singapore resident
>amerimutt
rent free

Anonymous

Anonymous Sun 20 Feb 2022 09:40:17 No.14248856 Report

Quoted By:

>>14248619
He's American on the inside

Anonymous

Anonymous Sun 20 Feb 2022 11:41:20 No.14249033 Report

Quoted By:

>>14248469
Nah sounds like a you problem

679KiB, 498x280, 5899C5C2-DD7A-42D5-B9B0-84081CAAC9F2.gif

View Same Google iqdb SauceNAO

Anonymous Sat 19 Feb 12:49:56 2022 No.14245658 View Reply Original Report

Quoted By: >>14249028

I need the power to control crows don’t ask there’s no time

11 posts and 1 image omitted

Anonymous

Anonymous Sat 19 Feb 2022 16:02:32 No.14246087 Report

Quoted By:

>>14246042
Mortys killing Mortys.

Anonymous

View Same Google iqdb SauceNAO crow up.jpg, 191KiB, 1000x563

Anonymous Sat 19 Feb 2022 16:11:56 No.14246106 Report

Quoted By:

>>14246056
That man is a hero.

Anonymous

Anonymous Sun 20 Feb 2022 07:03:50 No.14248602 Report

Quoted By: >>14248936

Can I train local crows to get skyniggers (pigeons) away from my roof, bros? They make me lose so much sleep. They start making their retarded noise at 5am and throughout the day as well.

Anonymous

Anonymous Sun 20 Feb 2022 10:40:21 No.14248936 Report

Quoted By:

>>14248602
Maybe if you become bros with a bunch of them and show them how much you hate the pigeons, but then you'll get crow noises. The crows in my neighborhood chill with the pigeons.

Anonymous

Anonymous Sun 20 Feb 2022 11:36:04 No.14249028 Report

Quoted By:

>>14245658
swedes are making crows dispose of cigarette butts.

5KiB, 284x178, itachii.jpg

View Same Google iqdb SauceNAO

Anonymous Sun 20 Feb 03:15:34 2022 No.14248228 View Reply Original Report

Quoted By: >>14248992

what happens after you die? can you explain it in a logical sense. what does science say ?

7 posts omitted

Anonymous

View Same Google iqdb SauceNAO desire.gif, 296KiB, 500x400

Anonymous Sun 20 Feb 2022 11:05:03 No.14248984 Report

Quoted By: >>14249010

>>14248969
>And vampyres too, but this one is much more scary, so I will not elaborate.

Anonymous

Anonymous Sun 20 Feb 2022 11:07:36 No.14248992 Report

Quoted By:

>>14248228
Can science create ocular techniques

Anonymous

View Same Google iqdb SauceNAO C4bkbdfXAAIvxQp.jpg, 64KiB, 638x680

Anonymous Sun 20 Feb 2022 11:16:19 No.14249010 Report

Quoted By: >>14249022

>>14248984
https://www.researchgate.net/figure/Parabiosis-Two-mice-are-stitched-together-sharing-a-common-bloodstream-Heterochronic_fig2_320846470

Anonymous

Anonymous Sun 20 Feb 2022 11:30:41 No.14249021 Report

Quoted By:

>>14248952
Why not? anaesthesia and blows to the head are proven to do just that

Anonymous

Anonymous Sun 20 Feb 2022 11:31:01 No.14249022 Report

Quoted By:

>>14249010
Thanks. I think I'm going to go outside and scream for a while.

24KiB, 462x188, Screen Shot 2022-02-18 at 10.56.27 PM.png

View Same Google iqdb SauceNAO

MOOCs

Anonymous Sat 19 Feb 03:58:09 2022 No.14244787 View Reply Original Report

Quoted By: >>14248155 >>14248163 >>14248712

Are these edx micromasters worth a damn to employers?

>https://www.edx.org/micromasters/mitx-statistics-and-data-science

or are these just cash grabs to sell hopium

tell me anon

12 posts omitted

Anonymous

Anonymous Sun 20 Feb 2022 02:31:35 No.14248155 Report

Quoted By: >>14248160

>>14244787
Those are meme degrees, you only take them for yourself and your own knowledge.
They teach you actually useful stuff but don't expect the employee ever considering them.

Anonymous

Anonymous Sun 20 Feb 2022 02:33:37 No.14248160 Report

Quoted By:

>>14248155
this, couldn't say it better

Anonymous

Anonymous Sun 20 Feb 2022 02:34:42 No.14248163 Report

Quoted By:

>>14244787
In India, certainly. Go do engineering. Than you can stay in the tradition of collapsing buildings.

Anonymous

Anonymous Sun 20 Feb 2022 08:11:34 No.14248712 Report

Quoted By:

>>14244787
desu, it's probably worth some marketing points with HR.

Anonymous

Anonymous Sun 20 Feb 2022 11:14:23 No.14249008 Report

Quoted By:

>>14248132
Higher education in US is a for profit business. All these meme degrees and courses are consumer products.

https://youtu.be/0_UJw3PO4CY

359KiB, 750x600, __ibuki_suika_and_hanyuu_touhou_and_1_more_drawn_by_yanagi_nurikoboshi__f85fc10918e428159742ddabe7cfad0e.jpg

View Same Google iqdb SauceNAO

/sqt/ /qtddtot/ - stupid questions thread

Anonymous Wed 09 Feb 05:18:06 2022 No.14204690 View Reply Last 50 Original Report

Quoted By:

Previously: >>14177922

>what is /sqt/ for?
Questions regarding math and science.
>where do I go for advice?
>>>/sci/scg
>where do I go for other questions and requests?
>>>/wsr/ >>>/g/sqt >>>/diy/sqt etc.
>how do I post math symbols (Latex)?
rentry.org/sci-latex-v1
>a plain google search didn't return anything, is there anything else I should try before asking the question here?
scholar.google.com/
>where can I look up if the question has already been asked here?
archived.moe/sci/
boards.fireden.net/sci/
>how do I optimize an image losslessly?
trimage.org
pnggauntlet.com

>where can I get:
>books?
libgen.rs
z-lib.org
stitz-zeager.com
openstax.org/
>articles?
sci-hub.st
>book recs?
sites.google.com/site/scienceandmathguide/
4chan-science.fandom.com/wiki//sci/_Wiki
math.ucr.edu/home/baez/physics/Administrivia/booklist.html
>carreer advice?
sciencecareergeneral.neocities.org/
>charts?
imgur.com/a/pHfMGwE
imgur.com/a/ZZDVNk1
>tables, properties and material selection?
www.engineeringtoolbox.com/
www.matweb.com/

General advice for asking questions here:
>attach an image (animal images are ideal. Grab them from >>>/an/)
>avoid replying to yourself
>ask anonymously
>recheck the Latex before posting
>ignore shitpost replies
>avoid getting into arguments
>do not tell us where is it you came from
>do not mention how [other place] didn't answer your question so you're reposting it here
>if you need to ask for clarification fifteen times in a row, try to make the sequence easy to read through
>I'm not reading your handwriting
>I'm not flipping that sideways picture
>I'm not google translating your spanish
>don't ask to ask
>don't ask for a hint if you want a solution
>xyproblem.info/

337 posts and 64 images omitted

Anonymous

Anonymous Sat 19 Feb 2022 22:26:11 No.14247398 Report

Quoted By: >>14247403 >>14247416

At what rate would a 70gram piece of lead cool down in a 50°F environment if its initial temperature is 150°F? How hot would it be after an hour?

Anonymous

Anonymous Sat 19 Feb 2022 22:27:50 No.14247403 Report

Quoted By:

>>14247398
depends on the surface area of the lead, air flow, etc.

Anonymous

Anonymous Sat 19 Feb 2022 22:30:37 No.14247416 Report

Quoted By:

>>14247398
that being said, if youre doing this experimentally, the solution is gonna more or less look like
$T(t)=100e^{-\alpha t}+50$
so you could take a couple measurements and figure out $\alpha$

Anonymous

Anonymous Sat 19 Feb 2022 22:48:07 No.14247481 Report

Quoted By:

remi if youre here please make the new thread

Anonymous

Anonymous Sun 20 Feb 2022 11:07:32 No.14248991 Report

Quoted By:

New
>>14247599
>>14247599
>>14247599

41KiB, 263x269, ufo-0.jpg

View Same Google iqdb SauceNAO

PROOF OF ALIENS ON EARTH

Anonymous Sun 20 Feb 10:49:28 2022 No.14248955 View Reply Original Report

Quoted By: >>14248968

You wanted it, you got it. Don't complain when it turns out to be weirder than you expected...
Just know you WILL be different after seeing this.

https://youtu.be/LMv1k49sAM0
https://youtu.be/VlRqTgobV3o
https://youtu.be/1Jvr4O7pG9I
https://youtu.be/3cnUAP0DnxQ

Capcode	All Only User Posts Only Moderator Posts Only Admin Posts Only Developer Posts
Show Posts	All Only With Images Only Without Images
Deleted Posts	All Only Deleted Posts Only Non-Deleted Posts
Ghost Posts	All Only Ghost Posts Only Non-Ghost Posts
Post Type	All Only Sticky Threads Only Opening Posts Only Reply Posts
Results	All Grouped By Threads
Order	Latest Posts First Oldest Posts First

Threads by latest replies - Page 674

Your latest searches

MOOCs

/sqt/ /qtddtot/ - stupid questions thread

PROOF OF ALIENS ON EARTH