Post whacky or neat math stuff

[Dauphin]

1.23118572377867

Is the highest precision I could get with the apparatus available to me.

[Dauphin]

Though I always get dubious at that level of precision that it is doing what it says it's doing.

[KrazyHorse]

That's why I truncated 5 digits before the end. I got exactly what you got to exactly the same level of precision.

[Lancer]

In the bar there's 5 gay guys and 7 straight guys and 9 chicks. Two more gays arive, then 3 more straight guys with 3 chicks enter. Then a gay guy and a chick departs. Then a bus arrives and 14 straight guys and 9 chicks come in, and then three straight guys come out. Then a dog sneaks in through the kitchen chased by the dog's owner who is gay.

How many gay guys are in the bar?

[Kuciwalker]

Originally posted by KrazyHorse
Because I don't have the numerical recipes library locally on my laptop, and writing the root finder took less time than sshing onto the departmental network, editing a file via terminal emacs and remembering the proper linking syntax.

vi FTW

[Kuciwalker]

Originally posted by KrazyHorse

      DO 101 I = 0, 100
        GUESS = (TOP+BOT)/2.0
        RES = AFUNKP(GUESS)
        IF(RES.LT.0.0) BOT=GUESS
        IF(RES.GE.0.0) TOP=GUESS
        PRINT *, GUESS, RES, BOT, TOP
 101  CONTINUE

aside: you can get a Matlab command-line for free at http://www.gnu.org/software/octave/. It's very very woo for this sort of thing.

[b etor]

Originally posted by Veritass
For more calculator fun, you can always multiple 37037037037 by multiples of 3, or 12345679 by multiples of 9.

Hours of fun for the whole family.

that IS fun!

[Dauphin]

Originally posted by Lancer
In the bar there's 5 gay guys and 7 straight guys and 9 chicks. Two more gays arive, then 3 more straight guys with 3 chicks enter. Then a gay guy and a chick departs. Then a bus arrives and 14 straight guys and 9 chicks come in, and then three straight guys come out. Then a dog sneaks in through the kitchen chased by the dog's owner who is gay.

How many gay guys are in the bar?

The correct question is 'How hot are the chicks?'

[Lancer]

The correct answer is 10. When it says '3 straight guys come out', it means they get added to the gay column.

[Grandpa Troll]

Re: Post whacky or neat math stuff

Originally posted by mrmitchell
I'm in Arkansas Governor's School (hence my absence lately) and we've been doing all this math stuff that you would normally never see in high school, and yesterday we did one thing (0.999=1) that I'd seen on here before. I know you all have more interesting ones, so please, share.

Mr Mitchell, congrats on Governors school, our daughter was outstanding female participant at Governors School West in North Carolina, way back when. She was Valedictorian at Southwest HS in Onslow County. She went on to graduate from UNC Chapel Hill with a major in Biology then Wake Forest School of Medicine and is now a full time PA in Carolina Beach, near Wilmington NC

Again, that is a most prestigious school!

Congrats

Gramps

[Kuciwalker]

Re: Post whacky or neat math stuff

Originally posted by mrmitchell
I'm in Arkansas Governor's School (hence my absence lately) and we've been doing all this math stuff that you would normally never see in high school

I missed this bit. You're still in HS?

[Grandpa Troll]

Old Guy Math

I never attended a college or University. In fact when I was in school, you needed one year of general math to graduate HS.

I do miss the many math courses I wish now I had taken.

I design Concrete mixes. It is amazing to me how you come up with the yield. It is based on a Theoretical value in relationship to the Specific Gravity in terms of disbursing a Cubic Foot of Water. I am not adding any genius or neat equations here, jus sharing that it is to me awesome how math is used and just how important it is.

For instance the variables of ambient temperature and water temperature directly effect the yield when a degree or two comes into play.

This is probably of no signifigance to most here, but to design a concrete mix, with all that goes into it, from the Fineness Modulus of determining the qualities of fine aggregate (sand) to gradations and sieve analysis to determine whether or not a coarse aggregate meets or exceeds ATSM C 33, the absorption of various materials, the LOI (Loss On Ignition) of a Pozzolan or the fineness of the grind of cement to determine the set times, the hardness of the Stone(Los Angelas Abrasion Test).

To me its amazing how this all comes together to make the concrete we use on our highways and bridges and driveways we hardly ever give a second thought to.

Ok

I was just sharing how wonderful math is and if your still in school, study because chances are you may need it one day!

Gramps

[KrazyHorse]

Originally posted by Kuciwalker


aside: you can get a Matlab command-line for free at http://www.gnu.org/software/octave/. It's very very woo for this sort of thing.

Dude, when I want to do any serious math stuff I have the resources. I just don't do it on my laptop. I ssh into the departmental computers.

Seriously. I have more numerical methods experience than you do. By a long shot.

[Lul Thyme]

Originally posted by Ari Rahikkala
There is only one way to put a finite set into a linear sequence, up to isomorphism.

Never heard of a linear sequence, at least in a technical sense.

I'm thinking you might mean a total order?

In any case, isomorphism has different meanings depending on context. It means "whatever mapping preserves what structure you are interested in".
I'm guessing you mean a permutation in this case?

Why wouldn't this be true of say the set of integers?

If by a linear sequence you mean you are given a first element, and to every element in the sequence, a succesor (that's what it seems to mean to me intuitively), then that's just a bijection with a subset of the positive integers.

On a related note, at some point I remember thinking that something would be good to post next time we had a thread like this, but I can't seem to remember it now, so let me think about it.

[Lul Thyme]

This isn't really what I wanted to post, but some might find it interesting.

This is a problem called the Collatz conjecture which is very easy to state (at least as easy as Fermat's Last) but considered very hard.

Paul Erdõs (very famous 20th century mathematician)said about the Collatz conjecture, "Mathematics is not yet ready for such problems."

Here it is (http://en.wikipedia.org/wiki/Collatz_conjecture for more basic info):

You start with a positive integer.
and you repeat the following:
-If it is even, you half it.
-If it is odd, you multiply it by 3 and add 1. (so if it was say 7, you would get 22).

The conjecture says that you will eventually reach 1, whatever you start with.


It's not only interesting on its own, but related to many other problems.

Turns out there's even a whole conference on this problem.

http://www.math.grin.edu/~chamberl/conf.html

I'll try to find some interesting problem that can actually be solved by some here.