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4:01 PM
@Khallil This may help.
 
@Khallil \usepackage, I believe is what you want.
 
It is indeed, @DanielFischer!
Thank you for the link, @Ice.
 
@WillHunting hahaha ha ha ha .... pffffff
 
@robjohn : $(N-1)$-cell is [0 1]x[0 1]x....(N-1)times...x[0 1].
@robjohn : A two cell is the rectangle region with vertices (0,0),(1,0),(1,1),(0,1).
 
@RajeshD just a hypercube... $[0,1]^{N-1}$
 
4:13 PM
yes
@robjohn
I remember someone tell me N-Cell in this chat room a while ago.
 
4:31 PM
I would like some feedback on these three books from people who have seen them. What do you think of Marsden's Calculus I, II and III?
The second edition was published in 1985. They were used to teach calculus in Berkeley.
Hello @TedShifrin
 
Hello, @Jasper. They were exceedingly idiosyncratic. They dealt with the derivative in terms of lines upcrossing and downcrossing the graph. The book wasn't particularly popular, even at Berkeley when I was there ... But it's written by two true mathematics scholars.
Hi @DanielF
 
@TedShifrin Hi! You need to ping me as Will Hunting now.
 
Nah, I don't :P
 
@TedShifrin The last line is good enough for me. I think I will use them to prepare for GRE calculus.
I always looked at analysis books. Recently I realised that a large part of GRE is calculus, and the material is not covered in analysis books!
 
1985 is kinda old, no?
 
4:42 PM
@IceBoy Yes.
 
Calculus hasn't changed much since 1700 ...
The best books are the older ones ... like Courant/John ...
 
@TedShifrin I looked at those but I did not like the style of writing.
 
We've just been watering down the calculus books since the '50's ...
 
then we should use the originals
 
I don't remember the multivariable part of Marsden/Weinstein, but they certainly understand that material way better than most mathematicians who write calculus books. Thomas had appalling understanding of that material, and it showed in his book. (He was an elementary number theorist, not a geometer/applied mathematician.)
 
4:50 PM
Stewart seems to be the most popular calculus text these days.
 
Stewart's Single Variable Calculus, @WillHunting?
 
@Khallil No, simply "Calculus".
 
Oh, that one. I read a bit on limits in that book about two years ago.
I was just curious to see what it was about.
I personally don't like the layout of the book.
There's too much going on, on each page.
 
I hate books with colourful pictures.
 
why?
 
5:03 PM
Because often the colours serve no purpose. Greyscale would do, or black and white.
 
I think Stewart Calculus is good for learning basic techniques of integration for example
But it's really un-rigorous. I'd be surprised if the word compact is used in that book :P
 
The three books by Marsden and Weinstein cost less than Stewart.
 
Ah ok
 
do you dream in color?
 
I've never heard of those
 
5:06 PM
@rehband Published in 1985, lol.
@IceBoy Yes.
 
@WillHunting What's wrong with that? The newest version of Rudin's analysis book is from 1976 I think :P
 
@rehband Yes, lol.
 
@WillHunting Old books are awesome. These things haven't changed too much in the past hundred years haha
 
24 mins ago, by Ice Boy
then we should use the originals
 
I think the price of a math book should never exceed 100 USD.
But there are many exceeding 200 USD.
 
r9m
5:19 PM
@Chris'ssis ya ... I saw the previous message :D .. but I had classes so couldn't reply :) .. Nice question :)) .. I did it in a similar fashion as @robjohn did it :) .. in a way similar to the the argument in the beginning of this :)
@Chris'ssis didn't see you posted it on the main :D
@Chris'ssis :D NICE !!
hehe ;) ,, I started from $\frac{1}{3}\log^3 2$ and came to the LHS :))
 
@TedShifrin Hi back. Are you enjoying probability so far?
 
r9m
@DanielFischer I am taking an analytic NT course .. can you refer some good problem books ? :-)
 
Sorry, @r9m, I have never looked in any analytic number theory book.
 
r9m
@DanielFischer okay :)
 
(I plan to do it, but there are so many other things to do)
 
r9m
5:29 PM
@DanielFischer our prof suggested Ram Murty's book .. I was wondering if there were other similar books :)
 
@r9m No idea. Is that a collection of problems or a textbook?
 
r9m
@DanielFischer its a collection of problems .. he didn't refer any text books .. so I'm doing it from Apostol's book and following class notes
 
@r9m lol, really? :-)
 
Apostol is said to be good, so that seems a good way.
 
r9m
@Chris'ssis ya .. came to me naturally .. I was laughing at myself =P
 
5:34 PM
@r9m OK :D
 
r9m
@DanielFischer Apostol's book has lots of problems in the exercise :) .. but I can't do many of them ..
 
@r9m Maybe I should also add I can finish it in one line. ;)
 
r9m
@Chris'ssis :D really ?!!! how ? :D
 
@r9m Set them aside for a while and come back to them later. They won't resist for too long.
 
@r9m Magic :D
 
r9m
5:36 PM
@DanielFischer okay :-)
@Chris'ssis LOL :D .. haha :D Cool :D
@Chris'ssis I wanted to put the $\psi^{(1)}(n)^2$ in my blog ... can I put an outline of $\psi^{(1)}(n)^3$ and $\psi^{(1)}(n)^4$ as an end note (not the proof) ? :-)
 
@r9m You can do anything you want to. :-)
 
r9m
@Chris'ssis I know that .. but I need permission from the problem creator (copyright issues :P ) :-)
 
@r9m lolll, in general I like my questions to remain here but since it was my will to post them, I cannot oblige someone not to do $X$ thing. That's why I say it's your decision to do what you wanna do. ;)
 
r9m
@Chris'ssis 'remain here' .. any one can read the chat transcript :-) so its not like a secret :-) .. but the truth is no one except for the people on chat.se visits my blog =P (even none of my class mates know I have a blog :P .. )
 
@r9m How do you know that people here are those that visit your blog? Do you see my/our IP(s)? :-))))
(both here and there? :D - - then I ask myself who you are :D)
 
r9m
5:51 PM
@Chris'ssis no not the IP's but the country (I can figure out most of the time)
 
@r9m hehe, nice! :-)
 
r9m
@Chris'ssis but the IP is displayed if you comment on sth :)
 
@r9m As regards the questions I'm not concerned, I'm full of ideas every day, and I'm going to mainly focus in my book on the brilliance of the proofs.
@r9m If I add in my book the Au-Yeung series and put there a proof involving the use of the dilogarithm, then the reader might be probably bored about that, but if the reader sees a proof at the high school level, then he will be very well surprised.
 
@Chris'ssis God I hope you release that book ASAP :P
 
r9m
@Chris'ssis I was concerned since you mentioned its going to appear in your book :)
 
5:57 PM
@r9m Hey. How's galois theory going?
 
@r9m Yeah, it is possible to add another elementary proof to the Au-Yeung series. That one will be there, in a very nice form (at least).
 
@rehband Perfection takes time.
 
@WillHunting True story
 
r9m
@BalarkaSen I'm a newb :) so first time experience -> NICE :D
 
@rehband Well, it's much work to do there. It might take more than I initially thought. I have lots of ideas, I have thousand of questions, but it's not enough. :-)
 
5:58 PM
@r9m Excellent. Where are you now? What book are you using?
Have you finished fields?
 
r9m
@BalarkaSen I'm just starting .. we follow Artin
@BalarkaSen ya
 
@Chris'ssis I understand :) Crazy!
 
Artin is cool.
My favorite actually.
 
I just don't like Artin defining all his rings as commutative.
 
@rehband Each problem and each solution must be a masterpiece! The reader must say "WOW" at every single page.
 
6:00 PM
@WillHunting I don't want my elements skipping around.
Thanks.
 
r9m
@Chris'ssis I have seen 6 proofs so far :-)
 
@BalarkaSen However, I do like them defined with 1.
 
@r9m :-)
 
@Chris'ssis Such a perfectionist. The book will be incredible :)
 
@rehband My books will come out in 10 to 20 years from now.
 
6:01 PM
@r9m Do you mind if I give you an exercises?
 
r9m
@BalarkaSen YES =P lemme finish the book exercise first ..then if I am literate enough to understand your problems .. I might give it a try :P
 
@rehband I mean I wanna make really happy all the readers of my books, to be very glad they have my book, to love it. :-)
 
@WillHunting Nice :D What will they be on?
 
@WillHunting you think too much about trivias.
 
@r9m Is it an abstract algebra class, or a class devoted specifically to Galois theory?
 
6:02 PM
@r9m =P.
 
@rehband I intend to write a series of books covering all major branches of mathematics, something like Bourbaki.
 
You should sharpen your skills, @r9m.
 
@Chris'ssis Love it.
 
@BalarkaSen Indeed. I have OCD, as you know.
 
r9m
@RandomVariable yes .. its an Abstract algebra class :)
 
6:03 PM
@r9m I am posting it nonetheless : Determine the group of automorphisms of $\Bbb R$ fixing $\Bbb Q$ pointwise.
 
@WillHunting I didn't even know Bourbaki -- just googled him.
 
@rehband WAT
 
@rehband It's a name for a bunch of French mathematicians.
 
Bourbaki and Lang are legends.
 
@BalarkaSen Sry :(
@BalarkaSen Whos Lang?
 
6:04 PM
@rehband WAT
 
@rehband Serge Lang.
 
@BalarkaSen Sry!!!
 
Who's Serge Lang?
 
@WillHunting Ahh! A number terrorist
 
A member of the newer Bourbaki.
 
6:05 PM
@Chris'ssis Have you ever done this problem? $$\lim_{n\to\infty} n \left( \sqrt[n]{ \int_a^b f^{n+1}(x)dx } - \sqrt[n]{ \int_a^b f^{n}(x)dx } \right)$$
 
@rehband That one is in Furdui's book.
 
@Chris'ssis Indeed :)
 
@rehband It's a cute one.
 
@Chris'ssis Do we do it with the Mean Value Theorem? And then Stolz Cesaro?
 
r9m
@BalarkaSen okay =P I'm illiterate :P thanks for reminding me that :P
 
6:08 PM
@rehband I don't think we need to make use of the Mean Value Theorem.
 
@r9m When I took abstract algebra, we used Gallian's textbook.
 
@Chris'ssis Interesting. How can we do it?
 
@r9m ? Are you saying that you can't solve the problem or do you mean that you cannot understand it?
I believe the statement of the problem should be well understandable to you.
 
r9m
@BalarkaSen atleast one of them (not sure which, maybe both) .. :P
@BalarkaSen kiddin :P
@RandomVariable we follow Artin's Algebra book
 
@r9m The problem is sneaky. I believe the sneakiest one in Dummit-Foote.
Not that it's the hardest, just tricky to handle.
 
r9m
6:11 PM
@BalarkaSen I see .. I have to give it a try ..
 
@r9m Sure thing. Hint of the week : never ignore additional structure. [$\Bbb R$ is more than just a field]
 
r9m
@BalarkaSen I have a disgusting course called Logic this sem =P .. its eating my nerves :(
 
@Balarka Let $T(n,p)$ be the group of upper triangular matrices with $1$s in the diagonal and coefficients in $\Bbb F_p$.
 
What is the reason for locking downvotes?
 
you can edit it to unlock them
 
6:14 PM
Compute the order of Aut$(T(n,p)$) as a function of $n$ and $p$.
 
still doesn't explain the reason, though.
 
gah matrices.
 
oh, it's the group of $n \times n$ matrices.
 
@rehband $$\displaystyle \lim_{n\to\infty} n \sqrt[n]{ \int_a^b f^{n}(x)dx } \frac{\left( \frac{\sqrt[n]{ \int_a^b f^{n+1}(x)dx }}{ \sqrt[n]{ \int_a^b f^{n}(x)dx }} - 1 \right)}{\log\left(\frac{\sqrt[n]{ \int_a^b f^{n+1}(x)dx }}{ \sqrt[n]{ \int_a^b f^{n}(x)dx }}\right)}\log\left(\frac{\sqrt[n]{ \int_a^b f^{n+1}(x)dx }}{ \sqrt[n]{ \int_a^b f^{n}(x)dx }}\right)$$
 
it'd take some voodoo combinatorics I guess.
 
6:15 PM
@mathh So that people cannot change them as and when they please. So that things will not become chaotic if there was a mad voter.
 
@Chris'ssis Interesting. I think I got it now with the MVT. I'll show you:
 
@rehband Do you see that I'm done in one line that way?
 
@Balarka Oh, is the question to compute the automorphism group of $\Bbb R$?
 
@Chris'ssis No, hold on I'll look harder
Ahhhhh
:D
 
@rehband $$\frac{x-1}{\log(x)}$$
 
6:17 PM
using $\frac{x-1}{\log x}$
 
@rehband Done without pen and paper :D
 
@Chris'ssis 1 sec. Oh yeah fuck! $$\sqrt[n]{ \int_a^b f^n(x) dx } \to \sup f(x)$$
 
@Chris'ssis But with marker and whiteboard, lol.
 
@WillHunting :-))))))
 
@r9m Is the class more than one semester?
 
6:20 PM
@anon It seems that eye is yours.
 
what's that supposed to mean?
 
@rehband Indeed! :-)
 
@anon I feel as if I am looking at you, lol.
 
@Chris'ssis So it conv to $\log(\sup f(x))$
I got the same thing using Mean Value Theorem, but not in one line
 
6:21 PM
you're not, @WillH
 
@rehband $$\sup f(x)\log(\sup f(x))$$
 
My rash is so itchy. I need to use hot water to get rid of the itch.
 
r9m
@RandomVariable our Algebra course has been divided into three semesters .. the first sem we did some basic group theory, the second sem .. we did rings fields and 4th sem we have galois theory ..
 
@Chris'ssis Yeah, I meant to write that, sry. Mind is blown! So good!
 
@rehband No need to worry about that! :-)
 
6:23 PM
great, someone's talking algebra! If $e$ is a basis, $e = (e_1, e_2, e_3, ... e_n)$, what does $e^k(x)$ mean?
 
@carpetjar No idea. Check the book.
The book should have defined the notation.
 
@WillHunting but I must browse the whole book to understand the notation, sounds like a lot of work.
 
@Chris'ssis I'll try to remember that trick :P
 
@carpetjar It helps if you have some experience. There is an index and a notation index, sometimes.
 
r9m
gn :)
 
6:25 PM
@rehband :D
 
@r9m: this page seems to have a bunch of – tokens inserted that keep the bookmarks from rendering.
 
@carpetjar what's the context? what's the book?
 
@robjohn Nobody did anything about chat.stackexchange.com/transcript/message/17495349#17495349 , but when I told him to shut up, he banned me.It's really sad, you have to tolerate any non sense any idiot tells you and still convicted.
 
@FractalHand Do you know how chat flags work?
Someone flags and then if enough people agree, he gets banned.
That is all there is to it.
I have been banned many times, no big deal.
If you don't like it, leave the site.
 
@WillHunting What if those people disagree because of the users rep?
 
6:31 PM
@FractalHand If they disagree that it is an inappropriate message then you don't get banned.
 
@WillHunting I don't want to leave the site, I just can't tolerate follies of idiots.
 
@FractalHand Whether they agree or disagree is not something you get to control. That is how an imperfect system polices itself, end of story.
 
@WillHunting Fair enough.
 
@FractalHand By the way, what did you say that got you banned?
 
@FractalHand was a comment flagged?
 
6:33 PM
@WillHunting He said something indirectly and I remarked on it directly.
 
@FractalHand What was your exact sentence?
You know, I really should be a mod, lol.
 
@WillHunting I answered harshly, but it was just the direct form of what he said.
@WillHunting Anyway, I don't care anymore, I just wanted to let you know.
 
@FractalHand if you were banned it was probably because a comment was flagged and enough people agreed that it was inappropriate.
 
@FractalHand Well, you have not answered my question but you don't need to. You know, I got banned once for saying "I just had a great shit" lol.
@FractalHand Yes, take it as a lesson learnt about how this chat works. It has no bearing on you in real life, so just fuck it.
2
 
@MikeMiller there is not any index here, all I have is context: it's on the beginning of Lagrange's theorem proof, i.e. "every quadratic form has a diagonalizing basis." It starts with: "We will start with writing quadratic form $Q$ in some basis $e = (e_1, ...e_n)$: $Q(x)=\sum_{i,j=1}^n b_{ij}x^ix^j=\sum_{i,j=1}^nb_{ij}e^i(x)e^j(x)$, so $Q=\sum_{i,j=1}^nb_{ij}e^ie^j$
 
6:36 PM
@WillHunting Fair enough boss.
 
@carpetjar It refers to the dual basis.
 
@MikeMiller so $e^i$ is $i$-th vector from basis dual to $e$, right?
 
Aye: $e^i$ is the functional that sends $e_i$ to $1$ and kills the other $e_j$.
 
@MikeMiller or it is $\cos(1)+i\sin(1)$ :-)
 
@MikeMiller thank you, would spend a lot of time digging for this information.
 
6:39 PM
@robjohn depends on the author, I suppose :)
 
6:53 PM
Hey quick question (I don't want the answer) WTF is a commutator
It says here "a commutator of G we mean any element of the form $aba^{-1}b^{-1}$ where $a,b\in G$"
So the set of commutators is $f^{-1}(e)$ where $f:G\times G\rightarrow G$ and $f(a,b)=aba^{-1}b^{-1}$ right?
/me prods @robjohn because this isn't worthy of a question
 
7:28 PM
No, that's the set of pairs of commuting elements
The set of commutators is precisely what they said @Alec: "elements of $G$ of the form $aba^{-1}b^{-1}$"
 
@MikeMiller but.... if the group is Abelian say there's only one
 
7:40 PM
Would it be correct to say that this is true? $$ \displaystyle \begin{aligned} \lim_{n \to \infty} \left( \sqrt{n^2 - 17} - n \right) & = \lim_{n \to \infty} n \left( \sqrt{1 - \frac{17}{n}} - 1 \right) = 0 \end{aligned} $$
Oh, wait. This seems like an indeterminate form.
I'll try L'Hop with $\frac{1}{n}$ as the denom.
 
@Khallil it's easier than that!
 
It is?
:/
 
As $n$ gets really big does $n^2$ and $n^2-17$ really differ by that much?
so does the square root of those things start to differ by much?
 
Nope.
 
So the square root of those things don't differ by much either ($n^2-17$ is slightly below)
So $sqrt{n^2-17}$ tends towards $n$ from below.
n-n = 0!
 
7:44 PM
Apparently the answer is 8.5. I'm not seeing it.
Oh my word. I copied down the question incorrectly.
Ahhhh ...
 
@Khallil on a serious note, you can't say lim n = lim sqrt(n^2-17)
You can say lim n > lim sqrt(n^2-17)
 
Hey, @Huy. Want to play some FIFA? Math is doing my head in.
 
Huy
@Khallil: Maybe in a bit. Busy just now.
 
@Khallil $\left(\sqrt{1+\frac{17}n}-1\right)n$
 
@Alec Yes, that's correct.
 
7:50 PM
@Khallil and $\sqrt{1+x}\sim1+\frac x2$ as $x\to0$
 
@MikeMiller the limit thing, or?
 
Is that part of the Maclaurin expansion, @robjohn?
 
@Alec That an abelian group has only one commutator
 
Oh okay, thanks @MikeMiller!
 
@Khallil you can do it that way... you can also consider $$\sqrt{n^2+17n}-n=\frac{17n}{\sqrt{n^2+17n}+n} =\frac{17}{\sqrt{1+\frac{17}n}+1}\to\frac{17}2$$
 
7:52 PM
And vice versa.
The "commutator subgroup" is defined to be the subgroup generated by the commutators; it's trivial iff G is abelian.
 
I just did that before you replied, @robjohn!
It's about time I got some rest. It's been a tiring week of work.
 
@AlecTeal Sorry, I was at the vet with my dog. A commutator tells how far from being commutative two elements of a group are. $[a,b]=aba^{-1}b^{-1}$. If $[a,b]=e$, then $a$ and $b$ commute.
 
So.... @robjohn my function thing was right?
 
9:01 PM
@Hippalectryon I have a question for you.
 
@Chris'ssis What is it ?
 
Prove in one line that

$$\sum_{n=1}^{\infty} (-1)^{n+1} \frac{H_{n+1}^2}{n+2}-\sum_{n=1}^{\infty} \frac{(-1)^{n+1}}{n+2}\left(1+\frac{1}{2^2}+\cdots +\frac{1}{(n+1)^2}\right)=\frac{1}{3}\log^3(2)$$
@Hippalectryon I know you like these questions ...
 
I love them :D
But I can't solve them :c
 
@Hippalectryon Solving things is not that important, but the art of mathematics is important.
 
True
Is that related to your latest MSE question ?
The one Jack answered
 
9:05 PM
:17529965
 
I need to learn what the Cauchy product and Abel summation are xD
 
@Hippalectryon At the moment when I posted the question I didn't know if that is a known result.
 
Isn't there some data bank somewhere ?
 
@Hippalectryon You never know when something you think you discovered first was actually discovered by someone else before you.
 
Wow that's cool to know :o
@Chris'ssis All the more reasons to discover more things :D
 
9:11 PM
@Hippalectryon hehe, true ...
@Hippalectryon Actually, the interesting point about the result above is not related to the one line proof, but the fact that you can do the job without using any special function. All you need is just some elementary manipulations and you're done.
 
What are 'non special functions' for you ?
Do you think it's useful to learn the Cauchy product for finite sums ? The formula is quite big, have you ever used it ?
 
@Hippalectryon You already asked that in the past and received an answer from Nebucadnezar I think. ;)
 
@Chris'ssis The for you was important :) Given that you use a lot of complex functions, I was not sure whether you were using 'special' as a personal or global word
You might have thought that for you, Gamma is not a special function
 
@Hippalectryon lol, you wanna be funny now. ;)
 
@Chris'ssis What's the limit of $\displaystyle \sum_{k=0}^n\frac{1}{\sqrt{(k+1)(n-k+1)}}$ ?
 
9:20 PM
@Hippalectryon Can't you compute that?
 
I'm not sure where to start. It's not a riemann sum, it doesn't look like any sum I know, I don't see how I could turn that into a useful integral ...
It's $\displaystyle\left(\sum_{k=0}^n\frac{1}{\sqrt{1+n}}\right)^2$
 
@Hippalectryon yeah, using inequalities is helpful
 
Well the limit is $\geq1$
in abs value
In mathematics, the nth-term test for divergence is a simple test for the divergence of an infinite series: If or if the limit does not exist, then diverges. Many authors do not name this test or give it a shorter name. == Usage == Unlike stronger convergence tests, the term test cannot prove by itself that a series converges. In particular, the converse to the test is not true; instead all one can say is: If then may or may not converge. In other words, if the test is inconclusive. The harmonic series is a classic example of a divergent series whose terms limit to zero. The more general class...
-_______________________________-
 
@Hippalectryon let me tell you one thing ... if you wanna catch me with these things ... just lol :-)
 
Solved -_____-
@Chris'ssis I was just stuck lol
Not trying to catch anyone
 
9:26 PM
@Hippalectryon I attend these thing even when I sleep profoundly ... :-)
 
Don't tell me you're sleeping right now :C
Why do you keep removing some posts ?
 
@Hippalectryon $\pi$
 
(ノಠ益ಠ)ノ彡$\Pi$
2
 
@Hippalectryon May I give you a hint? (maybe you don't want one)
:D
 
@Chris'ssis On what ?
 
9:40 PM
@Hippalectryon On your series?
 
I told you it diverges by the term test :)
>=1
 
@Hippalectryon that series behaves like $$\sum_{k=1}^{n-1} \frac{1}{\sqrt{k(n-k)}}$$ and $$\lim_{n\to\infty} \sum_{k=1}^{n-1} \frac{1}{\sqrt{k(n-k)}}=\pi$$ by Riemann sums
 
But it diverges :c
The one I posted
Owait
I posted the wrong one -__-
It's supposed to be the sum of the one I posted
ANd if it goes towards $\pi$ then it obs diverges
 
@Hippalectryon You know what? You just inspired me to create something new for you ...
 
:D
There should me more smileys :c
Im always happy
(。◕‿‿◕。)
 
9:55 PM
@Hippalectryon $$\lim_{n\to\infty} \frac{\log(n)}{n}\sum_{k=2}^{n-2} \frac{1}{\sqrt{\log(k) \log(n-k)}}=1$$
 
♥‿♥
 
@Hippalectryon This is one of the limits that are pretty troublesome if you met them in a contest, especially if you have no idea about the value of the limit. I mean it's deadly.
 
bloodlust
 
I gave something similar to more students, no one "survived". I mean no one had any idea about the value of the limit.
 
@MikeMiller Yes.
 
10:13 PM
@Chris'ssis Indeed, it looks weird. Little-oh estimates don't work.
Wait a sec.
Hmm. OK, maybe I wasn't sure.
 
@BalarkaSen This a limit from the art category, one needs some craft to finish it. It might put down even some professors.
In my opinion, it's not enough to compute it, but to produce art when you work on it.
 
Of course, but as you have seen before, different people thinks in different ways. A guy who does hard-core number theoretic estimates does thinking in a weird way.
And, never underestimate the power of number theory (wink)
 
@BalarkaSen Agree.
 
@Chris'ssis I have an idea for now (based on squeezing) let me see if I can finish it.
Aloha, @Ian!
 
@BalarkaSen OK
 
10:23 PM
Hello, @BalarkaSen
 
@IanMateus Have you finished that problem?
 
Hey.
 
Herro, @Khallil
 
@BalarkaSen Nope, I haven't been thinking about it. I was quite busy these days :(
 
@IanMateus Ahh, OK. You can ask for a complete solution anytime you want though.
 
10:28 PM
@BalarkaSen ok :) I'm into analysis these days. I don't know if it is the same in your country, but here analysis is the key for some good courses.
 
Have a good day/evening :) I'm off
┌─┐
┴─┴
ಠ_ರೃ
 
Same thing here. Yuck analysis.
 
@Hippalectryon You should have put that limit in your pocket ... and think of it once in a while ... :-)
 
This is probably an Earthly thing.
 
@IanMateus I like hard analysis (estimating, etc.) but soft analysis always felt a bit too... soft.
 
10:34 PM
@BalarkaSen What do you mean by soft?
 
10:47 PM
@BalarkaSen cool article. I'm reading the initial chapters of Spivak (compact sets, Heine-Borel, differentiation theorems)
 
@IanMateus Ah.
Spivak is mostly about soft analysis.
Apostol is hard.
 
@Balarka Yes what?
 
@BalarkaSen I think Spivak has better content that Apostol.
 
Oh ya? well you don't like the eagles :D
 
@Pedro everyone agrees. Except maybe Jasper, who likes some hipster book nobody's ever heard of.
 
11:01 PM
hipsters like the eagles
 
11:17 PM
@PedroTamaroff are you here? I have a quick question (not a math one, in the sense of any working or anything a more general one)
 
11:36 PM
5 hours ago, by Mike Miller
@Balarka Oh, is the question to compute the automorphism group of $\Bbb R$?
@PedroTamaroff I don't contradict you.
 
@Balarka Fun problem.
 
Merely pointing out that Apostol contains hard stuffs more than Spivak.
@MikeMiller Yes. Probably one of my favorite ones =)
(probably because I haven't seen much of continuous automorphisms)
 
@BalarkaSen Want a hard problem?
 
Depends on what it is about.
 
Fields.
 
11:47 PM
Fire away.
 
Let $F$ be a field.
Prove that $F^\times$ is a finitely generated group iff $F$ is finite.
 
The only obvious thing is that $F$ has nonzero char.
Looks fun.
 
I'm leaving, ping me or email me if/when you get it.
 
Nevermind, I noted that you have it on your profile.
 
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