Mathematics - 2013-02-07 (page 4 of 4)

@AkramHassan John von Neumann supposedly said "Young man, in mathematics you don't understand things. You just get used to them."If it worked for him, it can't be a real limitation. — Michael Greinecker 4 hours ago

draks...

9:20 PM

Are there any graph theorists around?

user19161

I draw the graph of $y=x$, LOL.

Charlie

@draks... That's no..oh, wait, it is a moon...

draks...

too large for a moon

it's a space station, oh no right it's a moon

Charlie

@draks... HAHAH

Argon

Hehehehehe

Charlie

9:22 PM

;)

user58512

@AkramHassan, the most significant was the real numbers

draks...

I expected: hohoho

Argon

huhuhuhu

Theorem

@Drakes : i only know what graph is and some matching :P

Ed Gorcenski

Goddammit all, I want to strangle the authors of every single one of these coding blogs I've come across

user19161

9:24 PM

Amazing, asker edited question again. I really hope they STOP this nonsense.

user58512

@EdGorcenski, have you seen coding horror

Ed Gorcenski

Yeah

user58512

hehe

Ed Gorcenski

It's not that it's bad. It's just that every single thing is presented from the mind of someone who knows what they're doing, and so they fail to explain the important parts.

user58512

@EdGorcenski, once his server crashed and turned out he didn't have any backups.. so he had to scrape his site of google archives

Ed Gorcenski

9:25 PM

It's like, "let me explain this elementary thing. Now here's this super complicated thing. Easy, right?!"

draks...

So does anybody know if "Finding a Hamiltonian cycle on bridgeless undirected planar 3-regular bipartite graphs with face bounds is still np-complete?" math.stackexchange.com/q/297508/19341

skullpatrol

@AkramHassan I like your question, maybe if you reword it and make it more focused it will help.

Akram Hassan

@skullpatrol it's already closed

draks...

@Theorem sounds like you are the one I was looking for...

Akram Hassan

@skullpatrol what's your opinion

Theorem

9:29 PM

@draks... : i don't think i am the right person . i have just started reading about some graph theory .

skullpatrol

@AkramHassan That doesn't mean permanently you can still reword it and try again :)

Akram Hassan

@skullpatrol you mean rewrite it?

draks...

@Theorem do you have to?

or just out of interest...

Theorem

@draks... : i am supposed to have to . because i will have to write exam sometime soon

:P

draks...

good luck then

skullpatrol

9:34 PM

@AkramHassan Yes,chat.stackexchange.com/transcript/message/8016519#8016519

user58512

@AkramHassan, do you know about platonism

Akram Hassan

i just saw platonism and formalism today

user58512

@AkramHassan, platonism is about a reality of mathematical objects outside our universe

draks...

No it's about holes, fire and shadows...

Theorem

@draks... : u got an answer to ur question

draks...

9:37 PM

nice picture...

Theorem

@draks... where ?

in the answer ?

draks...

by henning

yes

user19161

Ladies and gentlemen, I have capped for today. Thank you for your support.

Theorem

@JasonBourne : we support u .

for changing ur name

user19161

@Theorem Sorry, I am now Jacob Black.

Theorem

9:40 PM

@JasonBourne : i know but i can't send a message to jacob black

may be i need to refresh

Mr. Black

@JacobBlack : Ya now it workd

user58512

I'm too tired to work on my math :(

it's been along day

Charlie

@user58512 go rest

draks...

@user58512 dream about it

@Charlie your word seems to work like a command to everybody...I feel tired

pourjour

Charlie

@draks... sorry

pourjour

9:49 PM

can someone explain to me this part"k={....}"

draks...

i can hardly read it...

Charlie

click

user58512

@pourjour, it's just that tan gives the same values for multiple different angles

draks...

@Charlie ahhh

Charlie

;)

user58512

9:51 PM

@pourjour, so atan isn't enough alone to invert tan - you also have to add in the information about which quadrant (x,y) is int

pourjour

@user58512 but why they specifies exatly those three valeus {1,2,0}

user58512

@pourjour, because those are the ones which work for the arctan function they have in mind

@pourjour, if you have a definition of arctan, you should be able to find these k values

pourjour

@user58512 any courses about that?

user58512

@pourjour, you just solve it

pourjour

@user58512 ok thanks, I will try

user58512

9:54 PM

@pourjour, $$\arctan x = \int_0^x \frac{dx}{x^2+1}$$

do you use this?

pourjour

@user58512 not yet we just have general idea about integral

user58512

oh ok

what is your arctan?

pourjour

@user58512 which arctan ?

draks...

@user58512 $x$ as limit and inside the integral? bah...

user58512

@draks..., tell me sooner so I can fix it!!

I dont know why I did that

draks...

10:01 PM

@user58512 I'll star it for the transcript...

I would really say "I waited" but I was offline

@Theorem the answers needs an update...

pourjour

10:24 PM

$\theta = arctan(\frac{y}{x})+k\pi$

how can I find the values of k

user58512

@pourjour, if arctan only gives angle in a certain range, then k=0 for (x,y) in that range..

@pourjour, and now if (x,y) is in the next place, you will need k=1,

pourjour

can u specify

which range

user58512

@pourjour, efunda.com/math/trig_functions/images/arctan_plot.gif

pourjour

any how to solve it with calcul?

user58512

@pourjour, so arctan will always be between -pi and pi

pourjour

10:28 PM

@user58512 yep

how can I relate that with k

uisng some inequality !

user58512

@pourjour, so if (x,y) is in the part: -x < y < x then k=0

@pourjour, because that's where theta = arctan(y/x) is between -pi and pi

user19161

@draks You like graph theory?

draks...

yes, do you?

user19161

Nope.

draks...

why not?

user19161

10:36 PM

Well, I am not really into combinatorial stuff.

draks...

why not?

user19161

Well, just doesn't turn me on as much as analysis.

draks...

ouuhhh ...wait...

user19161

But there are people who do graph theory and functional analysis, haha.

user19161

Like the great Bela Bollobas, LOL.

draks...

10:39 PM

there's a place for everybody

So what's Jacob's favorite recently?

@JacobBlack "Alice Bourne" was not an option for a new name?

user19161

@draks... Nope. Why would it be? =)

draks...

I just "wonder"

Charlie

@draks... hahaha

@draks... 2Xhahahaha

user19161

Who is Alice Bourne?

Charlie

@pourjour Soufian , sorry, how are you?

draks...

10:44 PM

@Charlie What does your hebrew(?) symbol mean?

Charlie

@draks... letter m

pourjour

@Charlie I'm fine thanks and u?

Charlie

@pourjour can't complain, i think

user19161

@draks... I see some beautiful women when I google Alice Bourne.

pourjour

@Charlie means not bad :)

Charlie

10:46 PM

@pourjour or "not so good"

user19161

@draks... Not very nice of you...

pourjour

@Charlie :(

draks...

depends on your taste (not mine as well)

Charlie

@pourjour :/

pourjour

@Charlie any news?

Charlie

10:47 PM

@pourjour none

draks...

@JacobBlack you're right, sorry Alice

Charlie

I'm too boring

user19161

@draks... Haha, why "Alice"?

Charlie

5 mins ago, by draks...

I just "wonder"

draks...

Some days ago I proposed this to Jason Bourne

because he wondered a lot

Do you know him?

Charlie

10:49 PM

@draks... Jasper?

draks...

I thought Jason...

Jasper Jason Jacob who's next?

Charlie

@draks... Jason=Jacob=Jasper

draks...

Bourne is Black is?

user19161

Shh...

draks...

shh...

Charlie

10:51 PM

shh...

user19161

I just realised your background is black as well.

Charlie

the space...

draks...

join the dark side

we've got cookies

user19161

I fight the dark side...

Charlie

@draks... no, you killed my father

draks...

10:52 PM

Charlie

@draks... HAHAHAHAHAHAHAHAHAHA

you have allowed this, the dark lord twisted your mind until now, and now you became the very thing you swore to destroy

draks...

@Charlie I AM YOUR FATHER...

Charlie

@draks... NOOOOOOOOOOOOOOOOOOOOOOOOOO THAT'S IMPOSSIBLE

draks...

damn I only know the german version by heart. Help me Obiwan Kenobi

Charlie

@draks... quote the german version, i'd love to hear

draks...

10:55 PM

Gemeinsam können wir den Imperator stürzen und als Vater und Sohn über die Galaxis herrschen!

Charlie

Nicee!

Ich bin dein Vater

is the only thing i know

i don't even know if this is right

user19161

@cha You are black too LOL

Charlie

yes, fo shizzle my nizzle

draks...

@Charlie It's "Vater" but very nice

Charlie

@draks... the letter sounds like f, right?

draks...

10:58 PM

right

Charlie

my german is a lame

draks...

as my hebrew

Charlie

hehe

@draks... what part of germany are you from?

draks...

why M?

Charlie

@draks... the first letter of my name

draks...

11:00 PM

I live in Munich, but I'm from the northern part of Bavaria

where are you from?

Charlie

@draks... Ah Munchen

@draks... Brazil

draks...

let me help you with some special characters: ü ä ö

Charlie

@draks... I don't have them in my keyboard

draks...

copy-past'em

Charlie

I like to say Leipzig

schlüssel

draks...

11:02 PM

Then scream it till your neighbors show up...

@Charlie wunderschön

Charlie

@draks... yes, it's nice!

Ich bin ein wunderkind

draks...

yes you are

Charlie

:D

Danke

draks...

hey not bad

your "wortschatz" is quite large

Charlie

@draks... you think?? you made my day!

draks...

11:06 PM

In my opinion, the most important thing in a foreign country is to order a beer in the corresponding language...

Charlie

@draks... hahahaha

mick

hey guys. just passing bye , cant stay :/
just saying I edited my last question

@Charlie hi

Charlie

@mick Hi.

draks...

@mick very good

@Charlie I made yours, but mine is over now

Charlie

@draks... ow

draks...

11:07 PM

it's late here, so good nite folks

Charlie

deutsch bier

@draks... Guten nacht

mick

was sollen wie machen ? :)

draks...

deutsches bier. Gute Nacht.

mick

spass ?

draks...

CU

Charlie

11:09 PM

@mick passing BY

mick

@Charlie you like number theory ?

Charlie

@mick I kind like, but i don't know anything about it

mick

@Charlie Im like a frenchmen who speaks no french ...

Charlie

@mick please, tell me what's your first language

mick

@Charlie my last question was about number theory ... maybe you like it

hehe I speak alot of languages but im not very good at any :) @Charlie

Charlie

11:16 PM

@mick the first you learned

mick

@Charlie If you insist , Im not very fond of giving personal info

Charlie

@mick ??? it's not personal info

mick

@Charlie it is personal. But I will make an exception for you. Its dutch

2

Charlie

@mick aah

i had that in mind

mick

Did you look at my last question (about polynomials) ? @Charlie

Charlie

11:21 PM

@mick url?

mick

2

Q: Counting primes of the form $S_1(a_n)$ vs primes of the form $S_2(b_n)$

Let $n$ be an integer $>1$. Let $S_1(a_n)$ be a symmetric irreducible integer polynomial in the variables $a_1,a_2,...a_n$. Let $S_2(b_n)$ be a symmetric irreducible integer polynomial in the variables $b_1,b_2,...b_n$ of the same degree as $S_1(a_n)$. Let $m$ be an integer $>1$ and let $S^...

@mick ok

gotta run now srr

@mick bye bye

@Charlie sweet dreams

Charlie

11:27 PM

@mick so to you!

Jonas Teuwen

Yes.

Sweet dreams.

skullpatrol

►

Alexander Gruber

yao

anybody know if there's a proof online anywhere of stellmacher's theorem on $\Sigma_4$-free groups?

user19161

11:51 PM

Hello @ethan.

Ethan

hi

Paul Manta

Quick question: If I want to convert coordinates like (x - a, y - a) into polar coordinates, what do I do? How do I deal with the offsets?

Ethan

$$2\sum_{k=1}^n\ln(\sigma_0(k))(\frac{2k}{n}-1)=\sum_{k=1}^{[\log_2(n)]}\ln(1+\frac{1}{k})\pi(n^{\frac{1}{k}})+O(\ln(n)^a?)=\‌frac{ \pi(n)}{\ln(2)}+O(\frac{\sqrt n)}{\ln(n)})$$

seems to be true

lol

user19161

@ethan Are you Ramanujan incarnate?

Ethan

Don't say stuff like that

lol

user19161

11:54 PM

I am not sarcastic. I think you will be famous one day.

Alexander Gruber

what is $\sigma_0$?

Ethan

the divisor function

$$\sum_{d\mid n} 1$$

Alexander Gruber

number of divisors?

Ethan

yes

Alexander Gruber

ah kk

anybody not terrible with analysis here able to help me prove that if $f:\mathcal{D}\rightarrow \mathbb{C}$ is analytic and $f[D]$ is contained in a line, then $f$ is constant? (where $\mathcal{D}\subset \mathbb{C}$ is a domain)

Transcript for

$Mathematics$ Mathematics