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15:03
$$\LARGE \text{I'M SHOCKED BY THE RESULT I JUST GOT!!!}$$
$$\huge\mathcal{ME}\text{ }\mathcal{ TOO}$$
Hehe nice letter lol
@Chris'ssis Okay... I wasn't sure how many coefficients were generalized. I could see either the constant or the linear term being generalized. I think both should have relatively nice forms.
15:13
@robjohn Yeap.
@Chris'ssis Yeah, but that was Jack's approach, so I chose the residue approach
@robjohn I didn't look at that.
@TheGame O really?
@Sawarnik Yes ?
@Alex What would be the follow up question? :D
@Sawarnik Nothing appropriate. Do you have an Indian girlfriend?
@Alex Unfortunately no :P
@Sawarnik Is there a specific Indian girl that you would like as a girlfriend?
@Sawarnik You are only 14?
@Alex Yes.
15:32
@Sawarnik That's nice, you will live for many years...possibly.
Anyway as you were.
Are you saying yes to both questions? @Sawarnik
@Alex Sorry .. got disconnected :(
@Alex Perhaps [not very sure] :P
Wow, there are 3 Supermans, 2 Mean Squares and 1 Batman in this chat now, fascinating!
Batman!
@Alex Alex, you are from?
@Sawarnik Africa.
South-Africa?
15:43
Somewhere in Africa.
Sure.
Southern Africa.
Kenya?
Zim?
South Africa...
Oh lol ... plenty of Indians there :D
I am in this world, but I am not of this world.
@JasperLoy Then you must be a philosopher or a Martian.
15:47
@Sawarnik Yes in fact Durban is the city with more Indians outside India then anywhere else in the world.
@Sawarnik Do you watch cricket?
@Alex <big> Yes! <\big>
@Alex Girls in my school are very mean.
@Sawarnik Convert them into median or mode then.
@Sawarnik Who has a better test team South Africa or India? You are only 14, you have time to figure out mean girls.
@Alex Not sure, they haven't played for some time, so I don't know the current SA team :|
@Sawarnik :) Okay but South Africa ranked number 1. Before I go, what did you eat for supper/
15:55
@Alex Roti and sabzi :)
@Sawarnik Indian food is awesome. I want roti and sabzi.
Anyway C yer
C U :)
Meet u later :)
16:31
I have found an in my mind interesting sequence.
$${0, -(1/2), -(5/6), -(13/12), -(77/60), -(97/60), -(739/420), -(1583/
840), -(1583/840), -(1919/840), -(21949/9240), -(8343/3080), -(
111539/40040)}$$
@Alex still talking about roti? :)
> Let $L,K\in End_k(V)$ such that $L\circ K =0=K\circ L$. Show that $Im(L) \cap Im(K)=0$.
Any suggestions ?
@Sawarnik heheh what did the girls do to u
16:49
@r9m this one is another proposal that was sent to AMM (everything is recorded in my e-mail, when I sent it to them)
@r9m ask Donald or whoever you want to find the result of this one and see what happens. The result there is possible due to my research, it was UNKNOWN. (I give you the link (again) when you're on)
I doubt you can find it in any paper around the world.
I solved almost all open problems from Ovidiu's book (that's because in some cases I only solved some particular cases).
I also sent the result to Ovidiu.
@IceBoy No. I'm going to publish my book alone.
17:06
@DanielFischer Do you have time for a quick question? It's admittedly not all that interesting.
@IceBoy I need a large blackboard on my wall and then work some more ...
The Complete Guide to Series and Integrals.
@RandomVariable Let's see whether it is interesting.
If $\sum_{n=1}^{\infty} a_{n}$ converges absolutely, is it necessarily true that $$\int_{0}^{\infty} \frac{x}{1+x^{2}} \sum_{n=1}^{\infty} a_{n} \sin (nx) = \sum_{n=1}^{\infty} a^{n} \int_{0}^{\infty} \frac{x \sin (nx)}{1+x^{2}} \ dx? $$
That should be $a_{n}$ on the right side.
17:22
Hmmmmmmmmm. I suspect it is, but since $\frac{x}{1+x^2}$ isn't integrable, it is not immediately clear that it holds.
@DanielFischer I also suspect it's true. But I don't know of any theorems that say it's true.
Okay, let's call $$f_N(x) = \sum_{n=1}^N a_n \sin (nx),\quad f(x) = \sum_{n=1}^\infty a_n \sin (nx).$$ Then all $f_N$ are $2\pi$-periodic functions with mean $0$, and $f_N\to f$ uniformly. Let $A = \{ x \in [0,2\pi] : f(x) > 0\}$, $B = \{ x \in [0,2\pi] : f(x) < 0\}$. We can use an alternating series argument to see that $\int_0^\infty \frac{x}{1+x^2}f(x)\,dx$ exists as an improper Riemann integral. Since $\lvert e^{inz}\rvert \leqslant 1$ in the upper half-plane, $f$ is continuous in the closed
upper half-plane, and holomorphic in the upper half-plane. So we can use the residue theorem to evaluate the integral.
Hmm, slowly, we would need to see that $f(z)$ decays nicely as $\operatorname{Im} z \to +\infty$.
Yes, okay, no problem.
Err, Obviously I forgot to replace $\sin (nz)$ by $e^{inz}$ above. Imagine that done.
17:38
@DanielFischer When you said "no problem" what were you referring to?
Anyway, we have $$\int_{\gamma_R} \frac{z}{1+z^2} \sum_{n=1}^\infty a_n e^{inz}\,dz = 2\pi i\operatorname{Res}\left(\frac{z}{1+z^2} \sum_{n=1}^\infty a_n e^{inz}; i\right) = 2\pi i \sum_{n=1}^\infty a_n \operatorname{Res} \left(\frac{z}{1+z^2}e^{inz};i\right).$$
@RandomVariable That $$\lim_{\operatorname{Im} z \to +\infty} \left\lvert \sum_{n=1}^\infty a_n e^{inz}\right\rvert \to 0$$ sufficiently fast.
$\lvert e^{inz}\rvert \leqslant \lvert e^{iz}\rvert$ on the closed upper half-plane is enough.
@DanielFischer So the right side of that equation equals the right side of the other equation, and we're done? Actually twice the other one.
@RandomVariable Well, and a factor of $i$. Yes, then we're done.
17:54
@DanielFischer Thanks. I should have asked that on the main site so you could have posted that answer. It's quite interesting.
@RandomVariable Yes, it's not as uninteresting as you made it sound in the announcement.
I'd expect there is a real-methods-only proof too.
$$\int_0^{\pi/2} x \cot(x) \csc^2(x) \log(\sec(x))=?$$
I hope to avoid talking about my achievements, some will say that I definitely brag with them, and they will be right thinking like that since I talk too much about that these days even if I don't like to do it.
@Chris'ssis Please do continue :)
@TheGame lolllllll :-)
@TheGame Just see the beauty result of it $$\int_0^{\pi/2} x \cot(x) \csc^2(x) \log(\sec(x))=\frac{\pi}{4}$$
I wonder what would main MSE say about it ...
The point is to do all without touching special functions. With special functions anyone can be a superman.
18:11
@Chris'ssis I guess you have laser eyes irl :P
@TheGame :D
And we have only the lesser eyes :(
I do topologize for the flurry of questions, @DanielFischer, but can you help me with another?
@BalarkaSen How would I know before I know what the question is?
@Committingtoachallenge WAT. $\mathcal{O}^{1/2-\epsilon}$ makes as much as sense as magic floopskintunks.
@DanielFischer That was meant as a joke. Rhetorical.
@BalarkaSen Okay, rhetorically, I can help you with another, provided it's easy enough.
Say, isn't there a rule that forbids the letter combination "onnh" in usernames?
18:22
@DanielFischer I want to prove the Jordan Curve Theorem for non piecewise rectilinear (i.e., polygonal) curves. ;)
@BalarkaSen For general Jordan curves? For piecewise continuously differentiable Jordan curves?
Right.
I got a question. If I prove something is no larger than $n^{\frac23+\epsilon}$, where $\epsilon$ is any positive constant, and $n\to \infty$ but is finite, will I be right to say I proved that thing is no larger than $n^{\frac23}$, as I can always choose smaller epsilon.. no, right?
Those were two different options, @BalarkaSen.
What does it even tell me.
18:23
@DanielFischer Oh OK. The former.
@Studentmath No.
$\epsilon$ is positive.
@Studentmath $n^{2/3}\cdot (\log n)^{123456789}$
i.e., not $0$
But if I prove it's certainly smaller than $n^{\frac23+\epsilon}$, than I can say it's no larger than $n^{\frac23}$?
@BalarkaSen Wait until you have learned some singular homology.
Kids, always remember $.
@Daniel I don't mind it getting larger - if it gets larger it's fine, I have monotony to back my claim
On the other hand if I chosoe $\epsilon=1/n$, I am in problem.
Hence the question - if I prove it's certainly smaller than, I can say it then, right?
18:27
@Studentmath No, $n^x\cdot (\log n)^k \in o(n^{x+\varepsilon})$ for all $\varepsilon > 0$, but it's not in $O(n^x)$.
@DanielFischer I was under the impression that it was no easy proof?
Am I right?
@BalarkaSen Right. That's why I told you to wait until you got the necessary machinery.
I plan to study algebraic topology after getting through the general part but that time might never come.
@Daniel gah, so to prove what I want I need to prove it is certainly smaller than $n^{\frac23+\epsilon}$, and have $\epsilon$ as any positive, even dependent on $n$, right?
@Studentmath What, precisely, do you want to prove?
18:30
I want to prove that it is no larger than $\Theta(n^{\frac23})$
I studied closed sets.
Cantor set stuff is beautiful.
@BalarkaSen Try to be open about these things
@Alizter Already open setted.
Simmons introduces open sets before closed sets.
@Studentmath What is "it"?
Runs back to number theory
18:32
A component in a graph
You can't run forever from $p$-adics, @Alizter. And that day you'll regret not studying topology.
Later on I will prove it's no smaller than $\Theta(n^{\frac23})$ and conclude it is precisely $\Theta(n^{\frac23})$.
@BalarkaSen i have more than enough time to study topology
@Alizter use it
rather than doing flimflam integrals
The question is whether I can conclude it is no larger than $\Theta(n^{2/3})$ by proving it is certainly smaller than $n^{2/3+\epsilon}$ if I choose the right definition for the epsilon - i.e. just positive
18:37
@Studentmath No. $$n^{2/3}(\log n)^k \in \left(\bigcap_{\varepsilon > 0} O(n^{2/3+\varepsilon})\right) \setminus O(n^{2/3})$$ for any $k > 0$.
@DanielFischer has counterexamples to everything.
@Daniel Ahah. Although it greatly depresses me, thanks!
@BalarkaSen I have no counterexample to the Riemann hypothesis.
That's because RH is true.
Yes, that makes it very hard to find them.
18:41
Prove that

$$e^{\large2/\pi} \le \int_0^1 \ \frac{{(1+x)^{1+x}}}{x^x} \ dx $$
@TheGame ^^
@Chris'ssis Integrand blows up at $x = 0$. Are you thinking about PVing?
@BalarkaSen Nothing blows up.
@BalarkaSen Denominator is $x^x$.
Right. Duh.
So you are assuming that $0^0 = 1$?
It's obviously true @BalarkaSen
18:45
@BalarkaSen What is $\lim_{x\to 0^{+}} x^x$?
Otherwise you need to PV, as I have mentioned : $$\lim_{\epsilon \to 0} \int_\epsilon^1 \frac{(1+x)^{1+x}}{x^x} dx$$
@BalarkaSen What PV? This is just a waste of time.
@Chris'ssis So you ARE PVing.
@BalarkaSen Using Lebesgue integral?
@DanielFischer Heh?
I understand the integral as over $(0, 1]$ instead of $[0, 1]$. Otherwise it doesn't make sense.
18:47
@BalarkaSen It's a perfectly fine Lebesgue integral even if the integrand is left undefined at $0$. But since one can continuously extend the integrand to $[0,1]$, even Riemann has no problems.
Probably.
I am being nitpicky, @Chris'ssis ;)
@BalarkaSen you meet the same story here $$\int_0^{\infty} \frac{\sin(x)}{x} \ dx$$
Right. I understand that as integrating over $(0, \infty)$ instead of $[0, \infty)$
"PV" stands for principle value.
@BalarkaSen Yeap, BUT sometimes you need to be careful there. Near such points the integral may blow up.
@Chris'ssis Yes, exactly my point.
18:50
Make that $\int_0^\pi$, @Chris'ssis, with the upper limit $\infty$, one needs to treat it as an improper Riemann integral.
Thanks for clarifying.
@DanielFischer right
I'm thinking to post my inequality on main ...
hmmm, let me modify it a bit
This is so annoying.
19:10
A problem must look beautiful, isn't it? Then ...
Prove that $$ \int_0^1 \ \frac{{(1+x)^{1+x}}}{x^x} \ dx \le 4$$
I can prove this, but it seems harder to prove that $$2 \le \int_0^1 \ \frac{{(1+x)^{1+x}}}{x^x} \ dx \le 3$$
Well, I need the last result beyond the idea of creating things ...
Some upvotes are welcome
0
Q: Prove that $2 \le \int_0^1 \ \frac{{(1+x)^{1+x}}}{x^x} \ dx \le 3$

Chris's sisI need some starting ideas, hints for proving that $$2 \le \int_0^1 \ \frac{{(1+x)^{1+x}}}{x^x} \ dx \le 3$$ I already checked that with Mathematica that numerically says that $$\int_0^1 \ \frac{{(1+x)^{1+x}}}{x^x} \ dx \approx 2.577632915067858 $$

19:26
Why was Mhenni suspended?
@Alizter Again?
@Chris'ssis I looked at his account it says he is allowed back on Dec 25
@Alizter It's good to avoid any mess with the others, in general, there is no benefit from it.
@Alizter There is usually some clue in the user's recent activity, though inflammatory comments tend to get deleted.
Well it may be this
I should cut the gossip though
need to do some physics
20:10
hehe, I received some nice answers
Trapezoids
This is nice to be given in a math contest as the easiest question.
@Chris'ssis Look what I just found
@TheGame lol :-))))))))
20:26
@TheGame This one was down today
$${\large\int}_0^1 \frac{\ln^2(1-x)\, \operatorname{Li}_2\left( \frac{1+x}2\right)}xdx= \frac{81\,\zeta(5) }{32}+ \frac{5\pi^2}{16}\zeta(3) -\frac{\zeta(3)}8\ln^22+\frac1{15}\ln^52\\-\frac{\pi^2}{ 18}\ln^32- \frac{\pi^4}{15}\ln2+2\operatorname{Li}_5\left(\tfrac12\right)+2\operatorname{Li‌​}_4\left(\tfrac12\right)\ln2$$
A bit long :)
@Chris'ssis does $\operatorname{Li}_5$ and $\operatorname{Li}_4$ not have closed forms?
@Alizter No
@Chris'ssis how come?
If one day you are faced with the moral dilemma of doing something morally right to help other people and yet this thing is illegal and you could be punished for doing it, what would you do?
20:30
@Alizter if you refer at $x=1/2$, then no, there are not known other forms.
@JasperLoy depends on the severity of how illegal and how morally right
@Alizter Yes, you are right. And that is the difficult thing to answer.
Parking in the wrong spot to help a pregnant woman maybe
But killing prisoners etc.
@JasperLoy It depends on how tough the punishment might be.
@Chris'ssis Yes, thank you.
I ask because I have this dilemma for a few years already. It makes me think and think about it all the time...
I need to talk to my closest friends and my mum about it before deciding...
20:32
@JasperLoy For so many years?
@Chris'ssis Yes, I have been thinking of doing this thing (which is not well defined) for years, but I have not done it, because I am busy with other things like solving my own mental problems.
I think I will go running tmr!
@JasperLoy No today?
@Chris'ssis Well, it is 4.36 am now, so I will go to sleep, wake up and then go running.
@JasperLoy aaaaaaaaa, you never do things TODAY
:-)
@Chris'ssis @Alizter The moral question I just asked you has bothered me for years. It is very painful. In the end, I will have to make a decision and act accordingly and face the consequences.
In this sick world, too many sick politicians make sick decisions which cause others suffering.
@Chris'ssis You always say that. =)
20:47
@JasperLoy I agree with that. The point is we cannot change the world, I hope you don't plan to do a stupid thing.
@Chris'ssis Well, I won't be hanged to death I think, but they might put me into jail for I don't know how long...
horray 83 rep
@JasperLoy Events happen, but some people will never be changed. I often see in the interviews I have very stupid people that have no hope. What can I do?
@JasperLoy hi
@Sarah First time you say hi to me first, lol.
@Sarah Thanks to our instigation in chat.
20:50
@JasperLoy i read the transcript. Email?
@Sarah reply to my emails :P
@Sarah OK. I will share with you soon, if the moral dilemma is what you are referring to.
@BalarkaSen Why would picking up trash cans help? Surely putting trash into the trash cans is a better idea?
@JasperLoy Yes
@Sarah You need to put the colon before and not after.
Good thing I didn't become a surgeon.
20:52
LOL.
@JasperLoy someone (in an interview) was telling me he's a great mathematician but he didn't know how to compute $$\lim_{x\to 0}\frac{1-\cos(x)}{x^2}$$ without l'Hopital.
@Chris'ssis Hmm, OK. That's why I always say I am only a banana.
@Chris'ssis I can cheat with big o notation if that helps
@Sarah yeah, you can with some limited expansion. ;-)
@Chris'ssis I wonder can all limits be solved without L'Hopital?
20:57
@Sarah They should work without L'Hopital.
@Sarah I just answered back to you.
I remember somebody "proving" the derivative of something using L'Hopital on the function itsself
@Alizter What did you say in your emails? LOL.
@JasperLoy oh I was showing sarah stuff about fractional derivatives and stuff
stuff and stuff. Go my english!
@Alizter OK. I usually don't talk math with Sarah, LOL.
@Alizter Yes go. You're English.
20:59
@Sarah I am ashamed to say I had to reread that a bit to understand
@Chris'ssis How many hours do you sleep/night ?
@Alizter You know I am kidding right?
@Sarah yes.
@TheGame 4-6 hours
@Chris'ssis Sleep more !
21:00
7-9 hours
One day you're gonna be too tired @Chris'ssis
any hours I can find
My singing is actually improving, after declining for many years. For once, I think I can sing better than when I was 16.
@TheGame I often pass through such bad days, but I'll sleep enough when I die ...
@Chris'ssis If you don't sleep enough then you'll feel really drowsy from time to time
21:01
For those who sing, it is very important to sing only when you have slept well.
It's awful when I have that in class :/
@TheGame True, I know what you mean.
Erdos never slept much. He also loved only numbers... and amphetamines apparently.
@Alizter go to sleep you wee epsilon
Erdos is now scottsihshsh
$\text{drugs }\subset\text{ Erdos}$
21:04
You're right. Physics must be finished. Anybody here familiar with microscopic properties of Aluminium 2024?
@Alizter 2024 ???
@TheGame yes.
What is that
Used in planes or something.
I mean, what is it compared to normal Al
21:05
Some zinc alloy or somethnig
who knows
Oh, so it's not only Al. I see.
wait copper
96% Al, 4% cu
3.8 - 4.9% Cu
21:06
Close enough
90.7 - 94.7% Al
Chemistry is more fun than Physics at the moment.
:D
@Alizter What I do in chem looks like physics
I would rather be learning about orbitals than learning about engineering.
@Alizter :O
I'm exactly doing that :D
21:08
@TheGame I attempted several times, unsucessfully, to apply abstract algebra to a "perfect" chemistry
@Alizter What does that mean ?
Like when quantum physics behaves like the theory says
Oh lol
Chemistry works perfectly with theory in many cases
Most cases actually
@TheGame Sometimes no. For example determining the orbital arrangement of an element is a highly non trivial task
@Alizter That's not the same problem
21:09
Trivial for first cases
One can NOT determine the orbital arrangement of any element
@TheGame Yes.
The probabilities
Even for trivial cases we make some approximations
they are denser in certain areas
95% chance of appearing in a region
5% possibly on the other side of the universe
@Alizter We need some approximations for trivial cases, and many others for more complex cases
21:11
and here is where I run away back to number theory
@Alizter Those 95% regions are calculated with methods that uses those approximations
That's not pure theory
lalala prime counting function lalala
Actually, anything other than H has lots of approxs
As long has it has more than one electron, we can't really compute the charge they get
@Alizter I'm sure Lewis would have loved it though
@Alizter Mindblown, $H_2^+$ exists !
:O
21:23
I wish I didn't post that GIF. It is so annoying now.
Indeed, @Alizter. Très annoying.
Véri très
glares @Hippa
21:57
@Ted @Thegame \o
Wie geht's?
?
I ain't speak no German :P

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