@user127001 just leave a laptop in the back of the classroom with skype on autoaccept.

problem solved.

@user127001 I can sympathize with the time lost while commuting, but I would recommend against missing class. There are often things said in class that make a big difference in understanding the material. That's why they bother having classes.

plus there is often an interaction factor in class that is beneficial.

@user127001 Do I sound like a parent? :-)

@rob I am on the bus right now. About 15 min late and I think I will get there in another 15 min. so total 30 min. late. I departed ahead of schedule today but the buses didn't stop to pick me up so that wasted about 20 min.

If I don't go to class late then I just wasted money since I will just go back home immediately after I get off the bus

@user127001 Ah, so you are not just staying at home. That's good. $\color{gold}{\Huge\star}$

Rob I have never missed a class before. I am paranoid of missing out on some math secret the professor might just happen to say that day

@user127001 that is a paranoia that I can live with.

I am so thirsty because I ran to my second bus stop for a good 15-20 min

It's cold out and I'm sweating so much

@user127001 what's the temperature there?

Ok almost there. I'm going to sprint when I get off the bus

I am just upset that I actually left early yet I am late

@user127001 at least you're trying. Sorry about being late.

@anyone, here?

I'm here :D

@user18481 I'm not here, but I've been known to be wrong before.

@robjohn I'm a little confused- you can integrate things that are discontinuous on a measure zero set- but you certainly can't differentiate that. What does that says about the relationship between the derivative and integral? I always thought they were inverses.

How do contours to infinity work?

In a PID, is it correct that $ab=acd$, then $b=cd$?

@Anthony ah, the fundamental theorem of calculus holds only for integrals on $\mathbb{R}$, not the general Lebesgue integral

@Alizter You mean as used to evaluate real integrals?

Not quite for example Hankel contour?

@Anthony The Cantor function is a good example. where defined, it's derivative is $0$.

Hmm...

So integrals and derivatives are very different beasts, it would seem.

Yes, one starts with I, the other D, lol.

:P

Interative and Diffengal

@Anthony $\frac{\mathrm{d}}{\mathrm{d}x}\int_0^xf(t)\,\mathrm{d}t=f(x)$

there is no function that when integrated gives the Cantor function

otherwise, that holds and in that sense, the two are inverses.

@robjohn I joined ELL today, easier to get points there, lol.

Hey

@Alizter You mean you want to know how to compute them in general?

@JasperLoy what is ELL?

I think tho I am thinking about contours in the wrong way @Alyosha

@robjohn English Language Learners, it is in beta.

@JasperLoy ah. is it the points that matter, or the learning?

@Alizter And you want help in this? (I'm hardly an expert, but) in what way do you believe your thinking about them is not good?

Well basically it is not specifically to do with contour integration but I am trying to do something with this $$\int_0^t dx \frac{W(- \log x)}{\log x}$$

But I do not thing I am going anywhere with it

I was going to try and you know series expansion into analytic form.

However integrating term by term makes it diverge

That's the Lambert $W$ function?

yes

I believe that I am (yet again!) playing with non elementary stuffs

I should probabally study differential galois theory so that I can convince my self some of these integrals are wild geese chases.

I guess it will only work as $t \to \infty$, evidently.

Wikipedia says Louisville's theorem isn't actually differential Galois theory.

It can be proven with differential Galois tho

Done classical Galois yet?

at the moment

I have no idea what differential galois theory is, lol.

I understand the outline however I need to really get into the details

but I have exams so during summer will be better

Before I gave a break I think I was doing something with field extensions but I think I will have to relearn :/

I hate exams.

Well, nonmathematical ones.

I hate all exams.

Bah! they ask for a counting proof, and accept the non-counting answer.

I passed a german one today tho :)

A-A+

@Alizter congratulations!

@robjohn You should hit them with a ruler.

@Alizter I remember you are going to apply to Cambridge.

I never have to write german ever again

@JasperLoy I have decided for Triple maths, computing and physics at a level

@Alizter, so why you learn German

@user18481 We have to at school. I enjoy German the most out of French or Italian.

@Alizter I enjoy Germans, lol.

@user18481 I took German in college. Why not?

@ where is your school?

But my language skills are not too good.

@robjohn I am always deciding between studying French or German for grad school. What do you think?

@ Nothing. I am just curious.

@ I think it is common in Europe. But I am not sure in the US.

sigh my next exam is a Biology one...

@JasperLoy I took Latin in high school and German in college. I then took French and German exams for generals in grad school.

Our school did Latin, which was quite fun.

@Alizter I thought GCSEs were mid-May.

@Alyosha They are

mine start may 6th

during june I have 8 days to learn discrete mathematics

@robjohn Wow, you know so many languages!

@Alizter That can mean a lot of things.

Thats basic networks and crictical path analysis and shtuff

@JasperLoy not really. The Latin got me through the French that I needed to read a passage from a math book.

@alizter I wish I were born in the UK, your universities are good.

@Alizter I'd say that would be a good idea for anything but D1.

Oy I'm back.

@Alyosha I am taking it early so I don't have to see it again

@robjohn If I had to choose only one of French and German, which would it be and why?

I always thought that integrals and derivatives were one in the same, really. But they're just really different things….

@Anthony Yes, like we said, one starts with D and the other I.

@Alizter Still, you have to put every module you've taken so far on UCAS.

Including UMS for Cam.

@JasperLoy :(

@JasperLoy I'm interested to hear the answer :-p

@Alyosha I will try and do well after all I am taking ALL of the A level modules,

@robjohn I find that I like both France and Germany, I am still deciding which one to be reborn in in my next life, lol.

I also have to put some half GCSE I did a couple of years ago on my ucas form. I got an E in religious philosphy

@Alizter Wow, that is bad.

@JasperLoy I am at least a quarter German. I don't know if I have any French.

@robjohn Isn't it something like we are about all 100th related? So maybe some french somewhere ;)

But so the step function has an integral- does it's integral have a derivative? I mean…. Yes?

Ugh

I'm so confused.

Hi @Will

@Alizter Merde! now I won't be able to sleep tonight >8(

@user127001 I have changed my username again, it is now back to Jasper lol.

"Jasper lol" should be your name

@user127001 You may need to refresh your browser to see. So did you get to your class?

@JasperLoy again?! I have to refresh this chat room and then restart ChatJax.

@rob i was able to catch up and follow the class during lecture even though i missed the beginning

@robjohn I know! I am going to fix that one day

@user127001 very good!

@robjohn I could do so before 30 days was up because I created a new account.

hotkey mathjax to f5

@Alizter fix what?

refreshing and then having to re run mathjax

@robjohn Not have to refresh I guess.

It is so painful moving my mouse to my bookmarks

@Alizter wouldn't that involve a change to the site?

That's why I don't have chatjax installed. Chat is for me to chat, lol.

I don't think so?

When I refresh make the mathjax book mark run if I am in chat or something

@Alizter hmm... every time I refresh, the non-page based scripts need to be restarted.

yes, that is true

I really liked my old email address. Now that I have deleted it I will never get it back.

@JasperLoy I am lucky to have mine alizter@gmail.com

The professor was plugging his book during the lecture. I kind of want to actually buy it and ha e it autographed by him but my mom might find the book

@JasperLoy why did you delete it?

@Alizter Mine used to be jasperloy@gmail.com, it's gone forever since gmail does not recycle old addresses.

@robjohn I was stupid. I have done many stupid things out of impulse. However, I don't consider myself an impulsive person.

@user127001 why would that be a problem?

@rob she threw all of my textbooks out because she doesn't like me studying math

@user127001 Really? I think she needs help.

@user127001 wha?

@user127001 I don't understand that...

Does anyone have Spivaks calculus?

@Alizter It's always available online, lol.

Anyone have it in hard copy?

She is a very devout Christian and dislikes me studying math for whatever religious reasons (I'm not quite sure myself)

@user127001 I think she needs help, really.

So I have all my textbooks on my laptop and can only use e-textbooks from now on

@user127001 Mathematics has no opinion on religion. I can understand science with conflicting views ...

@user127001 I think your mum is crazy.

Well if you have Spivaks calculus you must agree that it is a weirdly shaped book.

Its really square rather than rectangular

@Ali I used to have the 4th edition

I also had On Manifolds

Doesn't fit with my maths books well

@user127001 I think you need to talk with your mum about the matter. If this persists, you should try to move out.

AHHH Economics tomorrow. I wish there was more maths than percentage calculation in it :(

@user127001 there is the passage that refers to astrologers as mathematicians and astronomers. It is a bad translation in current language.

@Jasper it's been an issue for 20 years I don't think circumstances will change. Just 3 more years to put up with until I can get accepted into a PhD program to move out. Otherwise I don't think I can work and study math full time without sacrificing my grades

@user127001 OK. My father drove me mad. Today, I have OCD and I may never ever recover, in which case I will have to be tormented until the day I die.

@JasperLoy What did he do?

@Alizter Too many weird things I can't describe here.

I am very sad. I don't know when or if I will ever live life normally again.

I used to have anxiety about "out of place things" but I think I grew out of it.

I have not been working for a long time. My mum is taking care of me now.

I still sometimes get annoyed with coat hangers being the wrong way round.

As in get up at night to check them but oh well.

Sometimes, I wish I don't wake up from my sleep.

@Ali toilet paper too? That happens to me

@Jasper don't say that man

@user127001 Anyway, I am currently on meds.

There is a guy in my year who memorized the quartic formula...

I mean I memorise weird things but that is excessive

@Ali I thought everyone did

however I do have it on my wall

I once memorised the structure of the 20 amino acids @Alizter.

@user127001 Hmmm maybe I should be a troll and tell him to memorise the quintic

I also memorised the structure of all the monosaccharides, lol.

However, the Krebs cycle was too much for me, lol.

@Jasper do you read alot of math nowdays?

I got 4A's for my A levels, a B3 for GP and 2 S paper distinctions.

@Alizter No, I am trying to get better before studying math and applying to grad school, but I may never get better.

what's GP

@user127001 It's like English, stands for General Paper.

I only got a second upper and not a first class in university because I was already afflicted with mental illness.

Well best wishes @JasperLoy I am off to bed and probably will not return here until summer. Bye @user127001 , @robjohn , @Alyosha :)

bye

@user127001 You should really change your username to Bart, lol.

@JasperLoy your icon makes me think of the blue screen of death from windows 9x era

@MickLH Ah, I change its colour from time to time, it is now "blue".

I stumbled on something simple and fun, the arithmetic and harmonic means of $x$ and $1$ converge on $\sqrt{x}$ using only very simple arithmetic, I'll probably still use newton though because it's flexible

@Jas lol