1. ## The Mathematics Thread

Talk about all Math related topics.

History of Mathematics
Math problems
Music and Mathematics
Math discoveries
Mathematics and beauty

Math Science Math  Reply With Quote

2. ## Re: The Mathematics Thread

Um... 2+2=♥?

Is that what you mean? Is that scientific math?  Reply With Quote

3. ## Re: The Mathematics Thread

I thinks PDEs are an invention of the devil. My 0,02\$ on math.  Reply With Quote

4. ## Re: The Mathematics Thread

When I was in high school, I was convinced I could create a formula where I just needed to bring in some data to solve all my problems.

Will that girl love me? F(♥)=0 ----> solve this and you'll know.  Reply With Quote

5. ## Re: The Mathematics Thread

I hate math and I'm bad at it. I should stay away from this thread.  Reply With Quote

6. ## Re: The Mathematics Thread

I think I failed my geometry quiz.  Reply With Quote

7. ## Re: The Mathematics Thread

Any of you tried to solve the Königsberg bridge problem?  Reply With Quote

8. ## Re: The Mathematics Thread Originally Posted by Caxxo Any of you tried to solve the Königsberg bridge problem?
>2 odd verticies.  Reply With Quote

9. ## Re: The Mathematics Thread

What is infinity divided by zero?  Reply With Quote

10. ## Re: The Mathematics Thread

Alright, this is for you AP mathematicians, this math problem has bugged me for years:
"Three guys walk into a bar, they eat, drink and then decide to leave, so, they ask the waiter for the bill, he tells them it'll be 30 dollars.
The three guys decide to divide the bill equally so each one of them has to pay 10 dollars.

The waiter walks to the cashier with the 30 dollars but the cashier tells the waiter that the three guys earned a Friday's special discount so the bill will be 25 dollars instead.

He gives five dollars to the waiter, who now walks back towards the three guys. However, instead of returning the five dollars he decides to keep (steal) 2 dollars, and gives back only 3 dollars. The three guys take each 1 dollar to make it fair.

So, if each one of them had paid 10 dollars and now they were given back 1 dollar each, that means each one of them paid only 9 dollars.

If we multiply 9 dollars by 3, that means they paid a total of 27 dollars, if we add the two dollars that the waiter kept for himself, that would be a total of 29 dollars.
We started the problem with 30 dollars... where is the lost dollar??!
"  Reply With Quote

11. ## Re: The Mathematics Thread

I'm taking Differential Equations this semester. I love it, the professor is awesome, but the class sucks. Our grades are based purely on online quizzes (three question multiple choice) and exams, of which our class has the most difficult (average on the first test was a 63). Very interesting material, though. There's a lot of neat tricks I've picked up. Euler's formula (e^ix=cosx+isinx) is my favorite, since I love the proof (Taylor series are one of my favorite mathematical concepts).  Reply With Quote

12. ## Re: The Mathematics Thread Originally Posted by Wagomu Euler's formula (e^ix=cosx+isinx) is my favorite, since I love the proof (Taylor series are one of my favorite mathematical concepts).
My brain explodes when x = pi. Originally Posted by IrishLuigi What is infinity divided by zero?
Undefined (but not an indeterminate form, iirc).  Reply With Quote

13. ## Re: The Mathematics Thread

I'm taking Linear Algebra next semester for fun, as I expected to be (permanently!) employed by then. I have a degree in Economics, and in econ we used matrices a lot, yet I was never required to take any serious mathematics courses in it and I don't understand why. That, plus game theory, would have simplified a lot of the descriptive/statistical analysis. Stuff isn't even relevant in Finance though.

I've come to realize that my Algebra training is insufficient for the "engineer" Calculus I'm taking, or at least the operations I sometimes use are wrong algebraically. This makes me sad/annoyed because I was always proud of my algebraic skills, so I guess I didn't get enough varied practice in the past.  Reply With Quote

14. ## Re: The Mathematics Thread Originally Posted by Aioria Alright, this is for you AP mathematicians, this math problem has bugged me for years:
You're looking at it the wrong way. Each guy paid nine dollars, but two of said dollars are in the waiter's pocket. When you say that the waiter took two dollars and the guys paid tewenty-seven, you have to realize that the two dollars the waiter took are part of said twenty-seven, whereas the remaining three dollars are in the customers' pockets.  Reply With Quote

15. ## Re: The Mathematics Thread Originally Posted by Kitsune Inferno You're looking at it the wrong way. Each guy paid nine dollars, but two of said dollars are in the waiter's pocket. When you say that the waiter took two dollars and the guys paid twenty-seven, you have to realize that the two dollars the waiter took are part of said twenty-seven, whereas the remaining three dollars are in the customers' pockets.
Haha, you solved it pretty quickly. It was supposed to be a math puzzle!! Thanks for the explanation!!

EDIT: Going back to the main topic, I only had to take up to Calculus 2 and that was almost 4 years ago so I don't remember much of it... Euler's formula?, Königsberg bridge problem?... those names just sound crazy.  Reply With Quote

16. ## Re: The Mathematics Thread Originally Posted by Aioria Alright, this is for you AP mathematicians, this math problem has bugged me for years:

"Three guys walk into a bar, they eat, drink and then decide to leave, so, they ask the waiter for the bill, he tells them it'll be 30 dollars.
The three guys decide to divide the bill equally so each one of them has to pay 10 dollars.

The waiter walks to the cashier with the 30 dollars but the cashier tells the waiter that the three guys earned a Friday's special discount so the bill will be 25 dollars instead.

He gives five dollars to the waiter, who now walks back towards the three guys. However, instead of returning the five dollars he decides to keep (steal) 2 dollars, and gives back only 3 dollars. The three guys take each 1 dollar to make it fair.

So, if each one of them had paid 10 dollars and now they were given back 1 dollar each, that means each one of them paid only 9 dollars.

If we multiply 9 dollars by 3, that means they paid a total of 27 dollars, if we add the two dollars that the waiter kept for himself, that would be a total of 29 dollars.
We started the problem with 30 dollars... where is the lost dollar??!
"
They pay 30. Then they are told it's only 25. When the waiter steals 2 of their change its 27. Which is what they payed. The mistake you probably made, is to to belive in what is written there. So did I on first pass. But it's not 27+2 but 25+2 that they have to pay. Add the 3 that they got back and you have 30 again. :)
Too bad stuff like this is not what they teach you in math at the university. I wish I shared your enthusiasm Wagomu.   Reply With Quote

17. ## Re: The Mathematics Thread

I love math! No, seriously. It's awesome. Originally Posted by Caxxo Any of you tried to solve the Königsberg bridge problem?
I actually took an entire class on graph theory (check out the history section for the Konigsberg problem). It's a very interesting branch of math and has nothing to do with calculus, analysis, differential equations or most of what people generally associate with mathematics. You might also be interested to know that the "super difficult" problems in Good Will Hunting are really just elementary problems in graph theory!

And Wagomu, if you really like Taylor series, you should check out other series-based topics like Fourier Series and Telescoping series.  Reply With Quote

18. ## Re: The Mathematics Thread

I'm taking Advanced Mathematics (the subject name may vary in another country) now and as far as I'm concerned, I like it. Though not much calculus involved so far(loves calculus). Just complex number conversion from Rectangular to Polar to Exponential and all.. I'm expecting it to be much harder soon to the point that I'll hate it as much as I hate Engineering Mechanics. Anybody wants to explain more about De Moivre's?  Reply With Quote

19. ## Re: The Mathematics Thread

I modified the normal economics major with math because your average pure econ major is a douchey buffoon here...

As such, I've so far enjoyed diff eqs. and discrete probability, and struggled miserably through linear algebra. Currently taking "The Mathematics of Finance" (which involves Black-Scholes Merton, Brownian Motion, and Ito), and I'm planning on Real Analysis next term, whatever that is.

Math grades are consistently my worst ones, but I like to think that that's just because it's totally the most legit and therefore appropriately difficult subject ever. My stupid friends getting straight A's in a series of comparative literature classes just don't get it.  Reply With Quote

20. ## Re: The Mathematics Thread

I dropped every form of maths two years ago.

Fucking hate it.  Reply With Quote