Mathematics

skullpatrol

12:32 AM

Hi @robjohn how are you?

robjohn

@skullpatrol pretty good... trying to figure out why I am getting a different answer than others for a particular sum

skullpatrol

icic :-)

robjohn

Found it! :-)

I forgot a factor of 1/2 at one point that got squared to 1/4 and then caused a problem much further down.

skullpatrol

Grrrreat!

:D

Studentmath

12:56 AM

Huh! Managed to prove the upper-tail Chernoff bound I was looking for myself!

Now just need to prove the lower-tail one..

Basically have to find some $x$ that will hold $e^{-x(np-a)}*(pe^x+1-p)^n=e^{\frac{-a^2}{2np}}$, I believe it's probably some $ln(x)$ where $x<1$ and thus it's equivalent to finding $e^{\frac{(1-x)(np-a)}{x}}*(px+1-p)^n=e^\frac{-a^2/2np}$

Which doesn't make it any easier..

The Substitute

1:22 AM

Off topic: I have to pass 2 out of three quals, and I need some advice. I am very confident I can pass 2 of the three but algebra is not my strong point. Is it a better strategy to (1) Focus way more on two of the three or (2) Give all three exams an equal amount of effort?

Ted Shifrin

2:04 AM

@Studentmath: Glad to see you're still safe and sound!

MrWho

2:18 AM

@TedShifrin Hi

@robjohn How you doing Rob?

@skullpatrol Where on earth are you man?

robjohn

@MrWho doing fine, how about you?

MrWho

@robjohn Well, nervous, I made payment for the freshman year today.

robjohn

@MrWho that means you start soon?

MrWho

@robjohn Unfortunately, I have to take some irrelevant ( general courses ) like US politics and stuff too. Yeah, 25 Aug

robjohn

@MrWho I was lucky enough not to have to take those classes. I guess AP or grades or something got me out.

@MrWho Good luck!

MrWho

2:23 AM

@robjohn They don't accept anything here.Oh, thanks.I was about to take Calculus I and II simultaneously but I have financial issue so I dropped the course and found one with less credit hour(general lesson)

robjohn

@MrWho where is here? If you don't mind saying...

MrWho

@robjohn University

robjohn

@MrWho guessed that, but okay.

MrWho

@robjohn I don't want to say it in public channel.If you have mail or something, I will.

robjohn

@MrWho No, that's okay. Is is a local school, or are you going out of state?

MrWho

2:26 AM

@robjohn I'm already international, so , out of state.

robjohn

@MrWho Ah, so you're already out of your home country...

MrWho

@robjohn Unfortunately, yeah.

robjohn

@MrWho So you're already in the area of your school. Are you in dorms or living off campus?

MrWho

@robjohn Off-campus, in fact, on-campus is for the wealthy groups !

robjohn

@MrWho Ah, that can be the case, depending on the school.

MrWho

2:30 AM

@robjohn Being off-campus is bad, because you can't go to school easily, more importantly, you can't connect to people and find last-longing friends.At least, for a shy guy like me, it is the case.

robjohn

@MrWho That's not necessarily true. It is easier in dorms, but you can still make friends living off-campus.

MrWho

@robjohn I am kind of new to the university, just don't know what I'm about to do.I seriously rely on the Ebooks rather than paper books because of their noticeable cost.

robjohn

@MrWho books are a major cost in college. Do you have loans or are parents helping?

MrWho

@robjohn Parents, I can get loans, but it's like trap, however, money is the main issue.

@robjohn I tried to get funds, but there is no available opportunity right now!

robjohn

@MrWho it's too bad that money affects people's education, but university employees need to live, too.

MrWho

2:36 AM

@robjohn Yeah, it seriously sucks, sad to say, I pay double of the price given to residence people because of being international, also I can't work more than 20 hours.No job available is the other thing, even if there is, it's not affordable because of transportation.

robjohn

@MrWho once you're there for a while, I bet you can find public transportation to a lot of places where you might work

MrWho

@robjohn I already use bus to go to school !

robjohn

@MrWho So you're far away from campus, not just a walking distance.

MrWho

@robjohn Yeah, it's hard, but I get used to it.

MrWho

2:58 AM

@robjohn Do you know the way to prepare oneself for a math competition like putnam?

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$Mathematics$ Mathematics