Mathematics

1:50 AM

Ursula K LeGuin died yesterday, and I am quite sad about that... :'(

Nicholas Kyriakides

Is it appropriate to post requests for paid help here?

I would think not, but I'm not in charge

Nicholas Kyriakides

Ok I'll refrain then - I'm looking for someone to help me out in some geometry-related programming tasks (paid). Is there any place where I can ask that that you know of?

Q: Showing that $(\partial_{z}f_{n}(z_{n}))^{k} \rightarrow (\partial_{z}f(z_{o}))^{k}. ? $

Anyone care to verify :>)

0

In the text "Function Theory of a Complex Variable" by Robert E. Greene and Steven G. Krantz I'm having difficulty verifying my proof to Exercise 41 on (pg.100) much of the details pertaining to the proof of $\text{Proposition}\, \, \, (1.2)$ can be seen in $\text{Lemma (1.2)-(1.3)}$ $(1.0)$ L...

proof-verification

I attended a talk that Krantz gave a few years ago---it was quite disappointing

:(

2:03 AM

@Xander what was the talk about , and what made it disappointing

Honestly, I don't know what the talk was about---something PDE-ish?

the problem was that he had slides that averaged around 10,000 words each, and he spent then entire talk reading his slides

word for word

@Xander ouch :'>(

indeed

well did you at least take notes :P

for a man that has written books on mathematical communication and writing, it was really, really unexpected and disappointing

hells no

no notes

PDE is not my field, and I barely care

2:09 AM

lel

and now it is time for dinner

later

see ya O/ @Xander

\o

3:00 AM

Rough day

What happened?

The marker for my analysis class Apperntatly opulent understand my work so they just gave me 2 or 3/5 for each question.

I spend a lot of time rewriting out my assignments so it's really frustrating to see the marker be too lazy to put in the effort to read what I have written.

How much reading?

I realize the way I think is odd and even when carefully written my writing can be a challenge to read but it is there job in some sense.

Not a lot I try and make my proofs short as possible 3 pages for the whole assignment 5 questions of rather large writing

Talk to your TA about it.

3:07 AM

For example I had an equation and I want to divide by p-t. So I say consider the statement with the division. Then I proceed to say well p-t could be zero what's this mean?

And explain it's a trivial case and everything is fine otherwise

Marker writes on the line I wrote this you can divide by 0 minus 3.

Cant*

I was so mad I was just going to drop the class

Why would you "get mad" about that?

If p-t is already in the denominator, then it can never be zero, but if earlier steps p-t is not in the denominator, then you can in fact reason about what happens if p-t is zero

Such case are often trivial, but sometimes the 0th case can have interesting solutions. Though markers in many courses for some reasons like to ignore the 0th case

which IMO is not a good practice

Yeah, stating restrictions is no big deal.

The 0th case is as important as other cases. In fact, in many ODEs, the 0th case when it is nontrivial is often a limiting case of the dynamics

Q: Can The Fusion And Fission Of A Group Of Atoms Occur Infinitely?

(Unrelated)

-2

I'm curious to understand if you can split a nucleus or multiple nuclei and combine them back together through fusion, vice versa. Thank you

quantum-mechanics energy mass-energy fusion

Viewing the answer in a purely abstract algebraic perspective, you get the following interesting structures:

1. a=>b+c -> b+c=>d -> d=>b+c
2. a=>b+c -> b+c=>a

The result, is a deductive system instead of an algebraic structure, and the identities involved are implications instead of equalities

Meanwhile, there exists implication algebras, but they are not the same as the deductive system mentioned above:

pdfs.semanticscholar.org/3f1f/…

http://www.jams.or.jp/scm/contents/e-2006-4/2006-37.pdf
In particular, these kinda behave like lattices

3:26 AM

@Secret I think what's important is that I addressed all the cases correctly...

@Faust This is true, one should ensure every case is considered whenever a proof is wrote. I also did the same kind of thing if I were you.

21 mins ago, by Faust

Marker writes on the line I wrote this you can divide by 0 minus 3.

Though , I am not sure if I parse this correctly:

you cannot divide by (0 minus 3) ?

I have autism there is no amount of time I can spend writing a proof down that someone will come and say oh yeah that's how I would of done it. But I pride myself on making sure that the statements are logically correct.

(you cannot divide by 0) minus 3 ?

Minus 3 marks

I see

3:30 AM

There is no logical reason why someone who scored 98% in Analysis I should get 60% on there first analysis 2 assignment. Especially when logically speaking everything I wrote was correct

I will say your marker is invalid since you have shown the 0th case gives a trivial solution instead of a contradiction, meaning logically speaking, p-t can be zero (unless some extra assumptions or constraints on the nature of p-t said you cannot) and thus no division by zero is made

Yeah I'm reasonably confident they didn't read what I wrote

(NB I am mildly aspergic thus I can somewhat understood about autism, to me that is not a problem. In fact, I think our group has the advantage of being able to ignore anything that is irrelevant and inefficient (social pretentious things..) and be very thorough at checking for a number of cases and the consistency)

btw, what actually is p-t?

Each is a real number but in the case p-t was zero then there was no point even making the division since the statement was already showing the desired result.

Essentially it just said 0=0

@Secret my work is very logically consistent but often the presentation of the ideas seems odd or perhaps illogical to a reader as they would never think to do it that way. But I don't think that means it's any less correct

I see
(footnote: when considering the 0th case is when you start the line saying suppose a=0, you need to make sure your expression that is wrote does not have a in the denominator, because then you will be dividing by zero in such case)

Getting 0=0 when you plug in the p-t basically means it is trivial as you said (because the other variables then does not matter on what value they are)

@Faust Presentation is important though. As you may have experienced how a lot of the times my messages are not so comprehensible to other people, and I do try to make effort to speak in their language to make them understand what the ideas mean

3:39 AM

Do you have the same marker for analysis 2 as you had for analysis 1?

This is especially true when it comes to proofs. you cannot expect your readers to have the same thinking logic as you do, thus your statement have to guide them and justify why it is valid in aways they can understand

Yeah so instead of writing the equation and claiming it was true. I said consider the following wrote the equation. Then I said this equation is nonsense if p-t =0 and proceed to explain why it was trivial then said assume it's not zero and the worked with equation to get a solution.

For me, I will do both for completeness, that is I will have a paragraph going through p-t =/=0, and a paragraph going through p-t=0. That way, the whole presentation flows

@Secret I understand that I spend usually 2 days on an assignment to get all the answers then anthor 4 or 5 trying to write it out so people can understand what I have written

At least twice is much time is spent on presentation and carefully writing it out legible than on the math

If your assignment allows discussion with peers, it might help to discuss with your peers (that you trust that they will not just copy answers) and see if they can comprehend it

don't worry, I spent 3x more time than my peers just to iron out my assignments, but it is worth it

3:44 AM

Yeah i never realized it was problem as I got 100% on every analysis 1 assignment and the only Mark I ever lost was on a midterm and it was for misunderstanding the question

You need to talk to the TA.

Either way if the person had put in the effort to read it I would of gotten over 90% easily.

^ to skullpatrol

Well I told the instructor I was dropping the course and asked if I could just audit the class

...or even the prof...

3:45 AM

(read: seconded, to skullpatrol's)

Make an appointment.

They were very upset cause they had put a very difficult question on the assignment that when students went to his OH he couldn't solve it so he proved a theorem to make the question signifigantly easier so people could do the assinment question it turns out i had solved it barehanded already so i sent it to the prof they were so impressed they told the marker to give anyone with such a solution a bonus Mark. I got 4/5 for that proof

first principles ftw

::applause::

Anyway he's going to remark it and wants me to stay in the class but in still really upset

Julius

3:54 AM

If a theorem in a paper says "For fixed $a$, $c\in\Bbb{C}$, $|ph(1-z)|<\pi$ and $|ph(1+z)|<\pi$, we have...", can it be that only $|ph(1-z)|<\pi$ or $|ph(1+z)|<\pi$ is enough rather than both at the same time? I'm having this doubt because later they say that the result is also true for large $z$

well to answer this question, we need to know what is the function ph?

Julius

complex argument or phase

Don't waste your effort being upset @Faust

Instead, use that effort for producing more meaningful results on the next assignment :-)