Things you don't need to know…

Originally Posted by Myrthos
Unless both a and b are 1.

Of course. I should have said that it in general doesn't hold for integers.

pibbur who stands happily corrected

Originally Posted by Ripper

Originally Posted by Jaz
Gah! Go away with your maths.
I know the rule of three …

This is what happens when someone divides by zero. I blame myself.

NUMBERS SHALL HENCEFORTH HERE DOMINATE THE POSTS OF MORTALS

FIND THE INDEFINITE INTEGRAL FOR SIN(X)/X WITH RESPECT TO X

pibbur who says MUAAHAHAHAHAHAHAHAHAhahahahaha. Twice.

The Integral from sin(x)/x := Si(x)

Mr. Taylor is your friend:

sin(x) = x-x^3/3!+x^5/5!-x^7/7!…
sin(x)/x = 1-x^2/3!+x^4/5!-x^6/7!…

Integral: Si(x)= x-x^3/(3*3!)+x^5/(5*5!)-x^7/(7*7!)…

The problem with this thread is that within the scope of inifinite knowledge each of us can only know a small finite amount. While no two of us probably know the exact same things and it is likely that each of us know at least one thing that no one else knows; the question is how much of what we don't know do we really want to know ?

Originally Posted by HiddenX
The Integral from sin(x)/x := Si(x)

Mr. Taylor is your friend:

sin(x) = x-x^3/3!+x^5/5!-x^7/7!…
sin(x)/x = 1-x^2/3!+x^4/5!-x^6/7!…

Integral: Si(x)= x-x^3/(3*3!)+x^5/(5*5!)-x^7/(7*7!)…

Yepp. I was a bit evil there. sin(x)/x is a simple, nice formula, so one might be tempted to find a simple formula for the integral. Which is not possible, you have to use a Taylor series, (which you can get as close to the real function as you want, of course).

But I admit this was perhaps a bit over the top. Many watchers have no experience with integration, and if they do, they (many of them) have forgot it.

So I'll drop plans plans for entertaining aspects of differential equations, Fourier series, and above all the Fast Fourier Transform.

pibbur who has to admit that most watchers probably doesn't find mathematics as funny as he does.

Originally Posted by you
The problem with this thread is that within the scope of inifinite knowledge each of us can only know a small finite amount. While no two of us probably know the exact same things and it is likely that each of us know at least one thing that no one else knows; the question is how much of what we don't know do we really want to know ?

I don't see the problem. This thread is for anyone to post trivial knowledge or whatever she finds fascinating, amusing but quite often completely useless. Which means that the thread will contain things not appreciated, even understood by everyone. That's as it should be.

It's not for posting serious stuff, we have the science thread for that.

You might say that the mathematics stuff was a bit over the top. Maybe, but the stuff I posted was things I find fascinating. Not necessarily interesting for most watchers. I liked it, so I posted it. You come across interesting stuff? By all means, post it here.

pibbur who himself, probably is a trivial and sometimes quite useless person. And who wonders why the editor here insists on writing "Things" With a Capital 'T'. And "Capital" as well as "With" With Capital 'C' and 'W'.

BTW: All things about Australia belongs here

Originally Posted by pibbur who
Yepp. I was a bit evil there. sin(x)/x is a simple, nice formula, so one might be tempted to find a simple formula for the integral. Which is not possible, you have to use a Taylor series, (which you can get as close to the real function as you want, of course).

But I admit this was perhaps a bit over the top. Many watchers have no experience with integration, and if they do, they (many of them) have forgot it.

So I'll drop plans plans for entertaining aspects of differential equations, Fourier series, and above all the Fast Fourier Transform.

pibbur who has to admit that most watchers probably doesn't find mathematics as funny as he does.

Please go on with the Maths… it is a fun diversion here from time to time…

Originally Posted by GothicGothicness
Please go on with the Maths… it is a fun diversion here from time to time…

Ok. Thanks.

Switching to Norwegian, since I don't know how to say it in English: Alt for GG!!

pibbur who is Real, and therefore has a least upper bond (around 191 cm).

sin(x) reminds me of [Sin], which reminds me that my son is currently playing the HD version of Final Fantasy X… it's kinda cool to watch him play a game I played when he wasn't even born yet. And I still know some stuff so I serve as sonny's walkthrough.

Originally Posted by pibbur who

<snip>

BTW: All things about Australia belongs here

Oi! (Some) Australian stuff matters to some of us!!

Originally Posted by Hurls
Oi! (Some) Australian stuff matters to some of us!!

Sharks? Spiders? Snakes? Kylie?

Pibbur who thinks that maybe all that needs saying (most likely far more) has been said, so he should stop insulting down under, and look for other countries deserving his attention. Sweden's too obvious….Who's next? Luxembourg? Monaco? Alabama?

Why not a poll to choose?

Originally Posted by Hurls
Why not a poll to choose?

Well, actually I have decided to stop that part of my posting.

Pibbur

Originally Posted by pibbur who
Well, actually I have decided to stop that part of my posting.

Pibbur

More about my posts making fun of Australia. If anyone has felt offended because of those posts, or thinks that it's been too much of it, I'm sorry. I never want to hurt anyone.

Anyhow, there are fine lines I don't want to cross, so I think I'll let it rest now.

pibbur who is only "nasty" to people he likes.

PS. For the record, nobody has complained to me about this. DS.

I really doubt that anyone here felt that you were offending anyone, and certainly not intentionally.

Well, I wasn't offended, in fact, amused.

Where Do the Calendar Months Get Their Names?

Originally Posted by Myrthos
I really doubt that anyone here felt that you were offending anyone, and certainly not intentionally.

I was gravely offended. Australia is the product of Britain's finest hardened criminals, and I think they've done a smashing job of reclaiming the place from all the snakes and crocodiles.

Well as someone who has ancestors who were the first assisted migrants (aka convicts) I think we did an ok job. Also, the more than doubling of the population post WW2, mainly immigration from Southern Europe, also has had a beneficial impact. As has, in my opinion, 99.99% of subsequent arrivals.

There is so called Euler Brick problem:
https://en.wikipedia.org/wiki/Euler_brick

In short, if we add the third dimension to pythagorean theorem (A² + B² = C²) with integers, does a "brick" with the space diagonal inside that has integer length exist?
Noone proved or disproved an existence of such one.



I'm sure pibbur will try to solve this one:
Find a box where A² + B² + C² = G², and where all four numbers are integers.
Noone succeeded.