12:00 AM
That's the worst excuse ever.

I value integrity too highly to entertain a thought such as this.

Alcohol cant make you do something you dont want to.
cept get sick.

I almost died from drinking once.

Yeah, alcohol just makes you unable to say 1+1=2

i almost died while drinking... does that count?

12:01 AM
My gf went to a party so I got my mom to drop me off there so I could make sure she was taken care of and ended up rinking way too much.

lol

what are you guys up to tonight?

I almost got eaten by a Cougar and its two yearling cubs

I'm reviewing exponential functions and logs and inverse functions.

@Faust Really?

12:03 AM
like an older woman?

@Dodsy sadly no. a really big cat tried to kill us while we drunk camping
luckily we had a boat and all got into it just before they hit the beach we were barely 10 feet out into the water when the mother came outa the bush
She was teaching them how to hunt

They're endangered here.
in ontario.

i got a couple dead ones around

If they need to eat humans they are really hungry

:(

12:05 AM
It's hard enough being human. Being animal is worse

the one in my living room tried to kill my grandfather

:(

But some animals do have it better than some humans.

it jumped off a rock bluff at him he heard turned and shot from the hip. lucky son of bitch killed it but it still knocked him out when it hit him.
it did fall 30 feet easily and hit him so not that surprising it knocked him out

Interesting story

12:08 AM
anyway dont mess with a cougar
bears save for grizzlys are panzies
but cougars they will kill you dead

Don't even mess with a dog. I am scared of dogs. I am a wuss.

I'm scared dying.

im pretty confident i can take a dog

Actually I am scared of cats too.

i cant figure out where i put my phone

12:13 AM
Give it a ring and you will know, lol

how do you find a phone w.o a phone lol

Some people have more than one?

user228700
Say, a function need not be continuous at a point for the limit at that point to exist, no?

hm.

@Kaumudi.H No need.
In fact, you don't even need it to be defined there, lol.

12:16 AM
Let's say that $\{x\in\mathbb{R}:[3,6]\}$ does a limit exist at 6?

user228700
@Dodsy No, I think, because we cannot approach this point from the right.

@Dodsy Doesn't make sense because you have a set there, not a function.

Right.
Exactly my point.
Carry on.
>_>

@Kaumudi.H Well, people do talk about one-sided limits.

user228700
Hehe, thanks :-) I was wondering why, then, my textbook says:

12:18 AM
note to self don't talk on math chat after drinking

user228700
> "If a function $f$ is differentiable at a given point, $x_o$, it is continuous at this point"

@Kaumudi.H Ah yes, differentiability at a point implies continuity at that point, easy result to prove. Follows from definitions.

okay then say we have a function $f(x)=\sqrt{x^3+6x^2+2x}$ it is not a continuous function
does it have a limit?
yes.
(I think.)
please nobody listen to me.

user228700
Lol.

user228700
@Jasper Definitions?

12:21 AM
@Kaumudi.H The definitions of continuity and differentiability

user228700
Ah, hmm, can you please give me the gist of how it follows from said definitions?

@Kaumudi.H It's true though, what's the limit as x approaches 3?

user228700
Uh, $\sqrt{87}$?

Yo

yo dami

12:25 AM

rock
@Dodsy that function is continous on many domains what you smoking?

:o
maybe you're right.
looks discontinuous to me.

its not continous on the reals

ah there it is.
on the reals!

@Kaumudi.H Anyway you will study some simple calculus proofs in first year college and more complicated ones after that.

12:28 AM
but (0,a) for all a>0 it is
well (a,b) 0<a<b it is lol

okay but using interval notation for the reals?
not just >0

wll you cant take the square root of negative numbers in the reals

exactly.
:D

so its not defined when x is negative
but all othe rvalues its fine

hmph
I thought we were only talking about $\mathbb{R}$

user228700
12:29 AM
@Jasper Lol, I am in my first year at university :-P

WHAT

so you must deifne a domain before you speak of its continuity

@Kaumudi.H Oh OK. I guess you must be in engineering so they don't teach these things, lol.

user228700
@Dodsy Lol, why, do I sound too dumb?

Faust shame on you.

user228700
12:30 AM
@Jasper Yep, yep.

@Kaumudi.H nah you sound very smart my friend.
we are not learning this in my calculus class (yet)

@Kaumudi.H If you want to stay in engineering but want to learn proofs, pick up books on your own and study.

user228700
Ah, I see.

12:30 AM
@Kaumudi.H if your in your first year you shouldnt be talking about multivarable calculus thats a third year thing

user228700
@Faust Well :-/

she's a genie @Faust

user228700
@Jasper ::Thumbs up::

user228700
Thanks, guys :-)

@Kaumudi.H Just want to add that googling and asking on SE is often not the best thing. The best thing is to read real books, lol.

12:32 AM
i like to fly turn invisble and one million dollars
2

you can have whatever is in your fridge, faust.
also whatever you own will remain yours until you sell it or give it away.

Lite beer!?

ugh D:

user228700
@Jasper Ah, hmm, the trouble is that I might not have the time to do this.

Why is it that all of my contributions to the star board today have been ridiculous!?

12:34 AM
eh, your one from 33 minutes ago isn't ridiciulous

@Kaumudi.H Yeah, school makes you busy. It is also important to get good grades, so you should focus on your schoolwork first.

Alright... but none of them have involved math...

@Kaumudi.H engineering is cool.

user228700
@Jasper ^

I didn't get good grades because I was already sick. My GPA is only 4.49 out of 5.

12:38 AM
that's pretty good jasp.
so far i've received a single mark.
out of 81.

@Jasper grades dont matter so much in the first year

they do for me

is there a way to express $f(n)=1$ when $n\equiv 0,1\pmod 3$ and 3 otherwise with floors and such?

I'm thinking of transfering :3
due to gf wanting to not stay here.
though it's a great school.

my gpa was horrible my first year
and not good my second year

12:40 AM
@Faust Now the only thing that matters is that I can recover from my mental problems. =)

have you heard of uwo @faust

i actually did so bad the second semester of ym first year i got put on academic probation

it's actually the floor of $3\left(\sqrt{x^2-3}-2x+3+3\operatorname{floor}\left(\frac{x}{3}\right)\right)^{‌​-1}$ but I'm looking for a more elegant form

D: sorry to hear that faust
glad you made a turn around.

end of last year the chair of the math department invited me to go into any honours program i wanted in the math department

12:42 AM
but faust

so dont be too worried about ur first year just work on the material and stay away from girls.\

HA girls.

When you make a turnaround, at some point your instantaneous velocity is zero, lol.

My gf is enough for me.
@Jasper very deep

@Dodsy that seems like a contradiction Western and Ontario

12:43 AM
@Faust I don't agree. I think love is the greatest inspiration in the world.

sigh.
I can't believe you haven't heard of it.
:(

i live in a little box

you're a country bumpkin?

mm no im just odd
i cant name 7 actors

brad pitt?
Dustin Hoffman?

12:44 AM
even if you let me name musicians as well

Selena Gomez?

i have heard of brad pitt

sad dude.

but i am rather knowledgeable of many real world things
not just biology chemistry and physics but mechanics electrical plumbing etc
i can fix basically anything even electronics
do i enjoy movies? yes

Do you know what edamame is.

12:47 AM
do i give two flaming shits what the actors are called? defiantly not
cheese?
peas?
im out of guesses
japanese sword?

beans, you were close.

they any good?

I like Mr Bean.

ya they're really good
you boil them and salt them
then eat the insides out :o
really tasty

did you know that boiled peanuts are Delicious?
3

12:51 AM
no :o

@Faust Yes, indeed.

@Dodsy if your ever in flordia and see a sign for boiled nuts you should stop its def worth it.

Boiled peanuts are often served in Chinese restaurants as an appetizer.

I am not huge on peanut
I don't often enjoy peanut in butter form.
nor do I like peanuts in my foods.

yeah i dont really like peanuts eithier
but boiled peanuts are ftw.

12:55 AM
hm

Peanut butter is the best thing that exists
Though I'm not fond of peanuts directly

I'm the exact opposite.

i dont mind the odd deepfried breaded PB&J sammich
gotta get hot enoug to melt the peanut butter though

When I was a kid my mom would make me pb&j for lunch and it would always be smooshed

1:15 AM
I have it without jelly
In fact sometimes would just have a spoon of PB

i had a dog that fond of peanut butter in a similar way
it got run over by a tow truck.

You kids still here?!

Also @Balarka I figured out the problem from yesterday
The one about finite $T_0$ sets
It's easier to show that there's an open singleton and then look at opposite topologies

Love peanuts in Szechuan and Thai :)

@Ted so it seems. I don't have school right now so I'm not doing too much

1:23 AM
Well, we know you're a lazy bum, Demonark.

@TedShifrin i left and did some GT then came back stuck on some graph theory hw
For every pair of integers k and l, where $2 \geq k \geq l$, construct a connected
graph $G_{k,l}$ that has a dominating set X of cardinality k as well as a minimal
dominating set Y of cardinality l, but no dominating set of cardinality less than
k. Explain why X and Y are minimal dominating sets, and why $G_{k,l} has no dominating set of cardinality less than k. can anyone dicipher that 'Tis true, though I have been trying to do a bit of k-theory and finite topology so there's that :P How can the minimal dominating set have greater cardinality than a random dominating set? So what's a dominating set? im assuming that$ K_{k,l} $in The h Bar, Sep 9 at 12:56, by heather no, i'm not going to just solve a problem where you haven't really put any effort in to make it understandable to others. 1:25 AM uh Oh,$X$ends up having to be minimal. Well, that's obvious, then. Dominating set for a graph is a set such that all the other vertices are adjacent to something in it Good for Heather.$K_{2,5} $has a dominating set of cardianality 2 and a set of cardinaltity 5 i think This is just language, Faust. I don't think there's anything substantive. Oh, duh,$k\ge \ell$. I was reading it backwards. 1:27 AM no i wrote it like a retard You have something wrong, Faust. Wait I think that's a typo, since$2 \ge k \ge l$is... quite restrictive Probably$2\le k \le l$Uh huh. yeah @Daminark got it That's what I figured. And then minimality should say$X$must be minimal if$Y$is. But how can$k<\ell$? I don't know no graph theory. 1:28 AM is$K_{k,l} $an example? Minimal just means you can't remove vertices from it In contrast to minimum I think$K_{k,l}$works @TedShifrin then you know more than i do I truly know none. I never took it and I never taught it. im trying to take as many diffrent branchs of math as possible Good choice 1:30 AM i got Number theory, graph theory, abstract algerbra, analysis and geometry this semester Harris, Hirst, Mossinghoff: Combinatorics and Graph Theory is what I recommend as a text. But yeah okay we just need to guarantee that you can't find a dominating set with cardinality < k if its complete bipartite thats fine do i need every set or just one? "every set"? i dunno i know nothing about graph theory every graph? 1:33 AM They're asking you to find a graph for any$k,l$such that you have a dominating set of cardinality$k$and a minimal one of cardinality$l$, and so that no dominating sets have$< k$vertices. When someone asks: Do you know X theory?, just say: Yes, it is the theory of X.$K_{k,l}$has those two sets you want, so all you've got left is to show that if you have a dominating set, it has at least$k$elements ($k$is the smaller one) how do i do that? Wait a second Wait I think that's wrong actually For$K_{k,l}$there's always a 2-dominating set Choose one vertex from each side hmm K 1:36 AM Because we're talking about the complete bipartite graph, you choose$p_1$from one side and$p_2$from the other side$K_{2,l}$So given a vertex, it has to be connected to one of them Well now you've lost information on$k$hmm ok I think what you need to do is not be complete, just be connected like a tree? 1:37 AM Maybe that'd work But the point is to create a bipartite graph with a side of$k$vertices and a side of$l$vertices Then put just enough edges such that each side is a dominating set But such that you can't just choose a tiny subset from each side and get everything Hmm Oh wait not connected actually Here's an idea I'm not totally sure if this'll work it says connected Oh frick okay that messes up my idea actually That's merpy lol What I had in mind was to choose$k-1$vertices and connect them in a 1-1 fashion to$k-1$(of the$l$) vertices on the other side, imagine the ladder but without the side support hmm 1:41 AM Then connect the last one to all of the remaining$l-k+1$vertices What about just a path? Oh that doesn't work for any$k$and$l$yeah i was think about intersecting two paths one of length k and one length l but it didnt quite work Okay I am gonna take the intersection of our ideas Okay so, to be able to picture this, draw$k$vertices on one side (vertically) and$l$on the other Then look at the bottom$k-1$vertices on each side ok Okay actually let's label them to make life better Say Call the$k$vertices (bottom to top)$v_{1,1},v_{1,2},\ldots,v_{1,k}$1:47 AM And call the$l$vertices$v_{2,1},v_{2,2},\ldots,v_{2,l}$Now we're in good shape So, draw the path that goes$v_{1,1}$to$v_{2,1}$to$v_{1,2}$to$v_{2,2}$and so forth This path will terminate at$v_{2,k}$were these vertices connected in the first place? Nope, we're building this graph from scratch ok thought so But yeah, then connect all the remaining vertices on the$l$side (meaning$v_{2,k+1}, \ldots, v_{2,l}$) to$v_{1,k}$I'll send a picture of the graph I have in mind for$k=4$and$l = 8\$ so you get what I'm doing

ok
i can visulaize it pretty well
im just not great with definitions specially when they aint in my textbook

1:52 AM
Oh okay, that makes sense
But yeah so, I'll let you double check this but I'm pretty sure this graph does it
It's connected

got it?

Yup

i have to grab the gf from the hospital

Oh, I hope she's okay

(she a RN or w.e and is off in 10 minutes)
ah she fine
she works there
anyway ill be back in 30 or so prolly

1:54 AM
Oh okay, phew, I thought she was there because she got hurt or something

what's the coolest mathematic topics to learn right now?

Aight, I'll email you. See you around!

dif geo is cool

and what's the most influential research in mathematics nowadays?

It's hard to order things linearly
PDE is the largest area of research, I think
In part because that's more easily applicable to the sciences, so gets more funding and whatnot
More generally, analysis
Number theory is also quite big, and is responsible for why a lot of algebra exists
As for the coolest, it depends on what you like. I'm into stuff like algebra (esp number theory), topology, and discrete math, and I'm not into geometry much at all as of now
On the other hand, Ted loves geometry. So try out a bunch of things and see what resonates with you the most @user2860452

1:58 AM
The problem is I like all of them
.-.
but I don't have time to learn all of them

What level are you at right now? High school, undergrad, etc?

freshman
undergraduate

Ah, so you won't likely have time to learn everything but you can get through a reasonable amount as an undergrad, to at least get a general feel