Mathematics - 2013-02-16 (page 1 of 4)

user19161

00:03

OK guys the new day has begun, now you may upvote me, LOL.

user19161

00:14

Hey @ethan

Ethan

@JacobBlack hi

user19161

@Ethan I notice your writing is improving on this site. Anyway I made some minor edits for you a few seconds ago.

Ethan

@JacobBlack Thanks

user19161

@Ethan You can get some books to practise for your SATs.

Ethan

@JacobBlack Where?

user19161

00:23

@Ethan Just look around, your library, bookstore, online, etc. I think those must exist.

Ethan

@JacobBlack I don't know if I really need to learn alot of new stuff maybe for the english part, should I just take alot of practice tests?

user19161

@Ethan Well, I think for starters you should get your spelling right, maybe I will try to correct all your spellings in chat from now lol.

user19161

@Ethan I think vocab is a huge part, you should look up those words you don't know on those tests.

Ethan

@JacobBlack I am probably going to take it in may, do you think thats enough time to study?

user19161

@Ethan Also, you really should try to make an appointment with some prof like I told you last year.

Charlie

00:26

haha @theorem called me Doctor! how cute!

user19161

@Ethan Well, actually it's not just the SATs but your grades in school, I think those will play a part too, so just try to work on your school grades as well.

user19161

@Charlie You cure bananas!

Charlie

@JacobBlack ???

explain

user19161

@Charlie You, a doctor, cure bananas like me, just a joke, lol.

user19161

Oh man, must I explain everything I say?

Charlie

00:27

@JacobBlack Ah :)

@JacobBlack when it's not clear, yes

@JacobBlack and don't be rude at me!

Ethan

@JacobBlack How do I figure out which schools I should try to apply to? I want to learn more mathematics

user19161

Why did someone retag the -1 times -1 question from arithmetic to ring theory lol

user19161

@Ethan Well, you need to look at a number of factors: cost, location, curriculum, etc.

peoplepower

@JacobBlack What other framework can you use to explain it?

user19161

But I think you will be a great mathematician in future, so don't forget me when that happens @ethan

Charlie

00:34

I only applied to one uni

user19161

@peoplepower Well, I think leaving it as arithmetic is fine lol

user19161

@Ethan I am not familiar with your system to that extent lol.

Ethan

lol

user19161

Scared people know your grades? Nothing to be ashamed of.

user19161

Nah, it is adults who say stupid things in the world today, not children.

user19161

00:37

Adults are too busy trying to teach children the wrong things in life that they forget to learn the right things from them.

user19161

Since you live near UCLA and UCLA is a great place for math, I suggest you apply there @ethan

Ethan

A recruiter came to my school two days ago

Charlie

Have you ever watched ballet, @jacob?

user19161

Also seeing a prof and showing him your work will definitely increase your chances of getting a place I say @ethan

user19161

@Charlie No, I think ballet is boring lol

Charlie

00:39

@JacobBlack stop saying lol

it's annoying

Ethan

@JacobBlack You think a profesor would have weight over me getting into a school?

user19161

@Charlie Haha, I love to say it lol

Ethan

lol

Charlie

@JacobBlack and you must watch

user19161

@Ethan I am just telling you all the factors that play a part

user19161

00:41

@Charlie Who do you like to see in ballet?

Ethan

@JacobBlack I really am having trouble with all the scheduling, I was on campus a week or two ago for some ap chemistry class I am taking, I talked to an undergraduate their he said I should just sit in on one of the classes

Charlie

@JacobBlack Svetlana Zakharova

user19161

@Ethan And WTF are you taking AP chem?

Ethan

yes, @JacobBlack do you think a teacher would get offended, if I unofficially audited one of there classes, and then asked for advice at the end?

user19161

With regard to AP, these are my 2 cents.

user19161

00:43

First you must find out if taking AP means you can still enrol for the classes or not in your system.

user19161

One might pass the AP, not be able to take the classes, and not know the material in those classes well enough.

Charlie

@JacobBlack YOU MUST WATCH!

Ethan

What do you mean?

@JacobBlack Yes I don't plan on taking the chemistry test, just the calculus one

user19161

Well, I don't know what your AP means exactly, the system might have changed also.

user19161

You see, some people take the AP and get credits for it so they don't need to take the class again later on.

user19161

00:44

But then this means they might not be able to take the class the usual way so that it counts towards their GPA later on.

robjohn

@Victor Sorry, I don't think I will be of much help.

Sgernesto

hi

Charlie

hi

user19161

Also, this means they might not learn the material properly from a normal class.

Ethan

Yes, I understand that

user19161

00:45

But like I said, I don't really know how AP works in your context, so FIND OUT.

Ethan

Find out what? I don't understand

Sgernesto

do you know geogebra?

i like it

user19161

Find out what AP means in your context, that is all I am saying.

Ethan

means what?

Im confused

user19161

Haha, I am the one confused here, because I don't know what AP means exactly. Get it?

Ethan

00:46

I don't understand

user19161

I just want you to be aware of what you are doing.

Sgernesto

today i've used a small program to draw evolutes, involutes

Ethan

What am I doing?

Charlie

@Sgernesto nice

user19161

@Ethan Yeah, because I dunno what your AP means.

Sgernesto

00:47

i wish geogebra had also that function

Charlie

@Sgernesto I never used geogebra :(

Ethan

@JacobBlack do you think a teacher at ucla would get offended, if I unofficially audited one of there classes, and then asked for advice at the end?

user19161

@Ethan I told you to ask for permission to sit in from the lecturer.

peoplepower

Taking the AP exams without taking the course is the trick because you don't have to waste time.

user19161

You see, everything you ask @ethan I have told you 9000 years ago.

Sgernesto

00:48

geogebra is great for elementary geometry

user19161

@peoplepower But there are 2 disadvantages like I mentioned above.

Charlie

@Sgernesto :D

user19161

So I am telling you high school kids to consider carefully.

peoplepower

@JacobBlack Of course, I was primarily kidding (not that I did not do that).

Sgernesto

@Charlie by the way i still don't know how to proof this sgernesto.files.wordpress.com/2013/02/…

Charlie

00:50

@Sgernesto i was looking...

Ethan

@JacobBlack How do I get permission, it all sounds like a pain, can I just sit through one of there classes, and then ask for advice when there not busy?

Sgernesto

i noticed this property using geogebra

user19161

@Ethan Send an email for the exact time and class you wanna attend.

Charlie

@Sgernesto fascinating

Ethan

@JacobBlack To who, I emailed some one in the math department, about a month ago, and I still haven't gotten a response

Sgernesto

00:51

Charlie

@Sgernesto this is crazy, but nice

user19161

@Ethan With regard to sitting in a class, the lecturer of the class.

Sgernesto

it's a similar construction

user19161

@Ethan With regard to showing your work, a professor in analytic number theory.

Ethan

@JacobBlack I don't want to sound arrogant

Charlie

00:53

@Sgernesto this reminds me a funny teacher i had

user19161

@ethan There is no point emailing the secretary of the dept, that will get you nowhere. She will go like huh, who is this Ethan???

user19161

@Ethan Therefore, send a polite email, QED.

Ethan

@JacobBlack I didn't I emailed, a bill duke, math.ucla.edu/~ntg

Sgernesto

the second picture is the construction of the tangent lines to a circle through a given point. the first one is the same but with an ellipse

user19161

I think most people won't mind giving you an hour of their time or letting you sit in on a single lecture.

Sgernesto

00:55

unfortunately i still don't know how to obtain the point of intersection of the ellipse and the circle

user19161

@Ethan If no response from the lecturer or prof, try another one, or try again but send at most two times.

Charlie

@Sgernesto ;/

user19161

Interestingly, many people these days don't even bother to give a reply saying "Sorry, no" they just ignore it, how sad!

Charlie

@JacobBlack maybe they don't wanna say anything

Ethan

I don't know if he even saw it, I sent it to his school email about a couple weeks ago

user19161

00:56

How long does it take them to type a few letters?

user19161

@Charlie In this case, they should say something.

user19161

@Ethan The prof in NT?

Ethan

Yes

Charlie

@JacobBlack maybe not

user19161

Any other candidates you have? @ethan

user19161

00:57

@Charlie Well, then they are not very nice people.

Charlie

just like not saying hi when someone appears

user19161

Sorry, but no takes only ten seconds to type.

Sgernesto

@Charlie there's this puzzle, draw a triangle given a side the sum of the other sides and the angle between them

user19161

That is different so don't mix the two @cha.

Charlie

@JacobBlack same thing

user19161

00:58

Don't mix up a banana and an apple.

Charlie

same politetness

user19161

It is not about politeness.

robjohn

@JacobBlack: do you think that this deleted answer is too close to Did's answewr?

user19161

Here, there is a matter.

Charlie

yes it is

user19161

00:59

Saying hi is not a matter.

robjohn

@JacobBlack Hi

user19161

Are you upset with me for some reason @cha?

user19161

@robjohn I won't reply.

Charlie

@Sgernesto o.o

Sgernesto

@Charlie supose you fix the given side AB, then the solution will be the intersection of an ellipse with foci A,B and the point C will be in the arc of circle

robjohn

00:59

@JacobBlack is it a gas?

Charlie

@JacobBlack yes, but i won't say it here

Sgernesto

that makes the angle C equal to the given angle

user19161

@Charlie Why are you upset? WTF did I do? I did nothing bad to you M.

Charlie

you never do anything, right, Jasper....

user19161

@robjohn Let me see...

Ethan

01:01

@JacobBlack I don't want to sound conceited, how many more do I email?

Sgernesto

what i don't know is to find the intersection of an ellipse and a circle that passes through the foci of the ellipse, using only rule and compass

i really think it can be done , since this question appears in a book

Charlie

@Sgernesto yes, probably :P

user19161

@rob After glancing a few seconds, and not reading a few minutes, I don't see much similarity between the answers. In particular, I think his comment was a little overboard.

user19161

@Ethan Try a couple more. You are not hurting anyone by emailing, so don't worry.

user19161

If people can't even say "Sorry, no" I think they have failed as humans.

user19161

01:06

That is, assuming they read the email.

Ethan

@JacobBlack Should I send any of my stuff in the email?

user19161

@Ethan No, not yet. If they can't be bothered to reply, don't show them anything.

user19161

They don't deserve to see your great work lol.

Ethan

Its probably not that great

robjohn

@JacobBlack Any time I answer a question he has answered, he complains if they are close. Even if they are, they are not obviously so at a glance. In those cases, I think that the differences in our approaches are significant, but I think he is worried about splitting the points.

Sgernesto

01:09

@Charlie for instance i know a construction to obtain the intersction points of a line and a parabola but i don't know a construction for the intersection of line and ellipse

user19161

@Ethan Neither is their work great. My prof said 90 per cent of research is trivial lol

user19161

@robjohn He is one of those with MORE downvotes.

Ethan

@JacobBlack I am sorry to bug you so much ,but would you mind looking over at my email before I mail it?

user19161

@Ethan You can email me now. Do you know my email addy?

Charlie

@Sgernesto how did you come up with those stuff?

user19161

01:10

Address lol

Ethan

ok

Sgernesto

well this construction i learned it

Ethan

I dont

Sgernesto

it's a usual exercise

Charlie

@Sgernesto interesting

user19161

01:11

@Ethan My actual first name dot last name at gmail dot com. You know my name right?

Ethan

@JacobBlack no

Sgernesto

@Charlie given two lines and a point draw the circles tangent to the lines that pass through that point

user19161

@Ethan Wait, you don't know who you are talking to all this while?

Ethan

@JacobBlack I stopped asking personal questions after a while, people don't usually respond lol

robjohn

@JacobBlack You mean he has given more downvotes than your average bear?

Charlie

01:12

@Sgernesto ooh

user19161

@Ethan You don't know that I am jasper loy?

Sgernesto

and the construction is the same

Ethan

@JacobBlack Jasper loy.. it sounds familear..

user19161

@robjohn WHo is my bear?

user19161

@Ethan Hey you don't even know my name, I think you should not email me lol

Ethan

01:13

Its ringing in my head, but nothing is coming out

user19161

I am disappointed...

user19161

I thought we were connected...

Ethan

we r

u know my name

user19161

OK OK.

user19161

You can email me.

robjohn

01:14

@JacobBlack Ah, you have not watched Yogi Bear... he was always claiming to be smarter than the average bear

user19161

@Ethan Read above.

Ethan

If I say my email in chat, will it get tagged by some info collecting service

robjohn

@Ethan Is this a new idiom... "what's your addy?" instead of "who's your daddy?"

Ethan

Jacob told me it meant address

robjohn

@Ethan Chat is collected by Google, but if you delete the chat comment, the webbot shouldn't have a chance to get it.

user19161

01:17

@amwhy See email.

user19161

@ethan You can email me now...

robjohn

@Ethan It does. I was just playing with the words.

Ethan

I don't know your email

user19161

I said my actual first name dot last name at gmail dot com.

user19161

Ethan!!! lol

user19161

01:19

@ethan With your IQ you should be able to email me now...

user19161

Nothing, IQ is a stupid test.

Charlie

why you don't write???

user19161

@cha You must tell me why you are upset...

Charlie

DONE

user19161

(removed)

Charlie

01:21

Did you get, @ethan?

Ethan

yes

user19161

With his IQ, he should be able to figure out himself.

Charlie

maybe you are not clear enough

user19161

(removed)

Ethan

(removed)

user19161

01:24

I am going to eat something.

Charlie

I am going to sleep.

Sgernesto

bye

Charlie

@Sgernesto Bye!

robjohn

@JacobBlack Ah, I will be walking Lilly and then getting dinner, too.

Bel

01:40

Hi guys is anybody still here?

amWhy

@robjohn FWIW - I think your answer is fine; I don't think the commenter had any basis for the comment.

robjohn

01:59

@amWhy Our ideas were similar, but the presentation and execution were significantly different

amWhy

@robjohn You're right: presentation can be key. And we're talking math, so something may be $x$ (and many might know that) but why it's $x$ and the explanations are what's key...

user19161

@ethan I have not gotten any email from you yet.

user19161

@robjohn Though there was once you posted an answer whose idea was the same as mine hours later lol

user19161

OMG @amwhy you are using Windows 8?

amWhy

@JacobBlack yeah...why?

user19161

02:14

@amWhy Not many people I know use it yet, you are so advanced lol

user19161

Anyway, if you use Windows 8, I suggest you try IE10.

user19161

IE has improved greatly, really. And I think it might be the best on Windows 8.

amWhy

@JacobBlack semi-advanced...in some ways, but pretty naive about how to use the "advances" full-force...

user19161

The last time I touched Windows was 9000 years ago.

amWhy

@JacobBlack Yeah, maybe I'll work with it again...I have thousands of favorites bookmarked here, and thousands on AOL, and hundreds on IE; most browsers are good about importing/exporting bookmarks, but not AOL

@JacobBlack That's right, you use Linux, yes?

user19161

02:17

@amWhy Yes I use Debian which is a little hard to install for newbies lol

amWhy

@JacobBlack hehehe...

user19161

@amWhy I save no bookmarks, no history, no cache, etc hahaha

amWhy

@JacobBlack I may email you this weekend; I got some pretty devastating news a few hours ago that I'm too dazed by to let it sink in...

user19161

@amWhy OMG

user19161

I have no more devastating news because my life is already devastated.

amWhy

02:20

@JacobBlack I hear you, bro! :-X

user19161

@amWhy HAHA, when did you start using bro like the great Jonas?

Orange Harvester

@amWhy Mail me. :-)

user19161

In this chat, Jonas is Batman, I am Superman.

amWhy

@JacobBlack Maybe I picked it up from Jonas...who knows

@OrangeHarvester I don't know your "addy"...is it on your profile?

user19161

@OrangeHarvester Why change?

amWhy

02:23

:8134188 got it. I didn't know that was you! I like the name!

Orange Harvester

@amWhy :-D

user19161

@OrangeHarvester Well, I like my email and should keep it.

user19161

(removed)

Orange Harvester

(Yes, people can get my email from there, so....)

user19161

But why worry? If that is the reason...

user19161

02:27

It doesn't really increase spam.

Orange Harvester

Hmm. Let it be. I am off to eat something, else my stomach will kill me.

See you later.

user19161

@ora I wanna ask you sth.

user19161

Where did you see Artin's second ed?

Orange Harvester

@JacobBlack secret :P

user19161

@OrangeHarvester Ah!

Orange Harvester

02:30

You want a copy?

user19161

This chat is now full of nuts, bananas and secrets.

user19161

@OrangeHarvester I would like to take a look at it.

Orange Harvester

okay. doing so.

user19161

Also, I would really like to take a look at Folland's Advanced Calculus.

user19161

These publishers don't even let me see the first few pages so I can decide if I wanna buy.

user19161

02:32

I have literally spent thousands on books.

user19161

Supposedly Folland's AC gets bad reviews...

user19161

But his RA is so well written I have faith that every book of his will be excellent.

Orange Harvester

Me too. My friends loan out books from me. Especially those I would now use as I am not into electrical engineering right now.

@amWhy I did not get your mail. :-/

user19161

Also I wanna see Stromberg's Classical Real Analysis, out of print.

amWhy

@OrangeHarvester Haven't sent yet ;-) ...will before end of weekend... I've gotten behind, lagging, in emails...gotta get back on it!

user19161

02:36

@OrangeHarvester You need to wait 9000 years to get an email from her.

Orange Harvester

@amWhy Oh okay, no problem, I thought might be you might have read my email address wrongly.

amWhy

@JacobBlack hahahahahaha...! I'm going to get better.

Orange Harvester

@amWhy Don't you have a mail client? Like Outlook etc?

It makes it trivially easy to respond to emails. Open them once a day, and just fire away.

amWhy

@OrangeHarvester gmail, aol, .edu,...

Orange Harvester

@amWhy Multiple emails! I know, that is why we have mail clients, they can handle multiple email accounts.

amWhy

02:40

I've just gotten out of the habit of emailing regularly...oh, yes, I have outlook...haven't used it on my netbook yet (which is all I've been using these days,), I'll get back to it...You're right, it cuts down on time, checking all accounts!

Orange Harvester

@JacobBlack Checkmail.

amWhy

I've got to do some computing "house-cleaning"...that's part of why I've gotten behind...lots of deleting and sifting and reorganizing to do, and synchronizing too.

Orange Harvester

:-) I hear you mate.

amWhy

I think I'm going to wind-down for the day and call it an early night...g'night, all!

Orange Harvester

Good night!

Garbage Collector

03:30

Hi guys, what is the difference between polynomial and multinomial? I am really confused with them. I cannot distinguish them.

Sanchez

@GarbageCollector, polynomial has one variable, multinomial has more than one.

Garbage Collector

@Sanchez Understood. Thank you!

Garbage Collector

03:52

Is $a\frac{1}{b}$ understandable without the $\times$ symbol in between?

anon

Is the word "understandable" understandable to those who do not know English? Understandability is relative.

3

At less advanced levels, it would create ambiguity thanks to mixed fractions (moreso when a and b are actual numbers rather than variables).

skullpatrol

@GarbageCollector Yes.

AlanH

Hi all

skullpatrol

hi

AlanH

are there any moderators in here?

or vets

skullpatrol

04:08

robjohn is a moderator and veteran.

AlanH

looks like he's afk

maybe i'll just post to meta then

@skullpatrol thanks

skullpatrol

np :)

Garbage Collector

@skullpatrol Thanks.

user19161

04:25

@GarbageCollector I would not write my fractions this way. I would use the times symbol or parentheses there.

Garbage Collector

@JacobBlack OK. Good suggestion! Thank you. Gong Xi Fa Cai!

user19161

@GarbageCollector However use one of the two, not both.

Garbage Collector

@JacobBlack Gong Xi and Fa Cai must be separated?

user19161

@GarbageCollector No, I mean use either times or parentheses, but not both.

Garbage Collector

@JacobBlack OK. I see.

@JacobBlack: In mathematics, is there an name for this property $a-b=a+(-b)$?

For example, we have a "commutative" property $a+b=b+a$.

Sanchez

04:40

@GarbageCollector, you define a - b that way, to be honest.

Garbage Collector

@Sanchez OK. it should be called a definition of subtraction.

One more question related to mathematical writing. Should I use $\equiv$ when saying an expression in another form rather than an equation? For example, $a+b\equiv b+a$ or $a+b=b+a$?

Sanchez

Depends on context

Say if you express an identity, like $a^2-b^2=(a-b)(a+b)$, you can use $\equiv$

An identity is something that is always true whatever numbers you put in

But if you are just doing symbolic calculations, or axioms in ring theory or so, I think using $\equiv$ would be strange.

Garbage Collector

$a+b\equiv b+a $ is an identity as well?

Sanchez

Depends on context

Personally I don't treat things like axioms in ring theory as identity

BenjaLim

04:59

@Sanchez hey

Transcript for

$Mathematics$ Mathematics