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Re: The Math Thread

Posted: 12 Dec 2012 21:33
by Anteroinen
OnyxIonVortex wrote: I don't see a problem... in Northern Ireland people start going to school at 4, not?

I see a problem, for that is far too early.

Re: The Math Thread

Posted: 12 Dec 2012 21:35
by Vortex
Yeah, but I gave that as an extreme. Most countries starting age is at around 5 or 6, in Spain for example the age is 6.

Re: The Math Thread

Posted: 12 Dec 2012 21:38
by azareus
I have family in France, and they start at 3, but it is mostly just kindergarten and things like the alphabet until they are 5-6 years old. So in the end most countries have about the same starting age.

Re: The Math Thread

Posted: 12 Dec 2012 21:39
by sundayfever
Most people start at 6, yes.
Well then, that explains it. We start when we turn 7. Some, like me, 6.

Re: The Math Thread

Posted: 12 Dec 2012 22:35
by Oleander
Saying that you just need a 'big exponent' is a bit misleading, though; it converges even for the exponent s=1.00000000001. it's not quite a complete explanation but I suppose it's acceptable for explaining to non-mathy people. I just brought it up because it might lead you to false conclusions like thinking that the sum of the reciprocals of the prime numbers converges because primes are relatively rare, or thinking that the sum of the reciprocals of other sets of numbers diverges, when they actually don't.

Re: The Math Thread

Posted: 12 Dec 2012 22:36
by Vortex
If you want a rigurous explanation, I can give it too, but something tells me you already know it :P

Re: The Math Thread

Posted: 13 Dec 2012 18:41
by Vurn
OnyxIonVortex wrote: The R means the real part of a complex number. For example, R(5+6i)=5. And the big sigma is a repeated summation (Σummation?). For example, Σ(i=1 to 3) 2*i = 2*1 + 2*2 + 2*3. Az explained it well.
The zeta function would be, for example, for s=2:
zeta(2) = 1/1 + 1/4 + 1/9 + 1/16 + 1/25 + 1/36 + etc. = 1.64493...
Az didn't explain the summation thing too well, but I think I get it now.
And a complex number I suppose is a real number plus an imaginary number? That's what I conclude after that "The R means the real part of a complex number. For example, R(5+6i)=5." part.

On the school thing - people go to school at the age of 7 here (altough, soon the age will be changed to 6 I think). When you start school, you learn the alphabet and basic mathematics - even though you technically learned it during kindergarten (at least I did). Wtf?

Re: The Math Thread

Posted: 13 Dec 2012 18:48
by Vortex
Vurn wrote:
OnyxIonVortex wrote: The R means the real part of a complex number. For example, R(5+6i)=5. And the big sigma is a repeated summation (Σummation?). For example, Σ(i=1 to 3) 2*i = 2*1 + 2*2 + 2*3. Az explained it well.
The zeta function would be, for example, for s=2:
zeta(2) = 1/1 + 1/4 + 1/9 + 1/16 + 1/25 + 1/36 + etc. = 1.64493...
Az didn't explain the summation thing too well, but I think I get it now.
And a complex number I suppose is a real number plus an imaginary number? That's what I conclude after that "The R means the real part of a complex number. For example, R(5+6i)=5." part.

On the school thing - people go to school at the age of 7 here (altough, soon the age will be changed to 6 I think). When you start school, you learn the alphabet and basic mathematics - even though you technically learned it during kindergarten (at least I did). Wtf?
Yep, a complex number is real + imaginary. There are more ways to write complex numbers, but all of them reduce to that.

And well, maybe they do that because there might be people who didn't go to kindergarten? I have no idea...

Re: The Math Thread

Posted: 13 Dec 2012 18:50
by Anteroinen
Vurn wrote:
OnyxIonVortex wrote: The R means the real part of a complex number. For example, R(5+6i)=5. And the big sigma is a repeated summation (Σummation?). For example, Σ(i=1 to 3) 2*i = 2*1 + 2*2 + 2*3. Az explained it well.
The zeta function would be, for example, for s=2:
zeta(2) = 1/1 + 1/4 + 1/9 + 1/16 + 1/25 + 1/36 + etc. = 1.64493...
Az didn't explain the summation thing too well, but I think I get it now.
And a complex number I suppose is a real number plus an imaginary number? That's what I conclude after that "The R means the real part of a complex number. For example, R(5+6i)=5." part.

On the school thing - people go to school at the age of 7 here (altough, soon the age will be changed to 6 I think). When you start school, you learn the alphabet and basic mathematics - even though you technically learned it during kindergarten (at least I did). Wtf?
In here it is 7, although I knew of one who started a year later for some reason (he was one my best friend, I can't believe I never asked). Most learn the alphabet in school, I think, at least I did. There are exceptions to that for sure though. I don't remember us having any alphabet in kindergarten, and certainly no mathematics. What is this stuff about people learning stuff in the kindergarten?

Re: The Math Thread

Posted: 13 Dec 2012 18:54
by Vurn
Anteroinen wrote: In here it is 7, although I knew of one who started a year later for some reason (he was one my best friend, I can't believe I never asked). Most learn the alphabet in school, I think, at least I did. There are exceptions to that for sure though. I don't remember us having any alphabet in kindergarten, and certainly no mathematics. What is this stuff about people learning stuff in the kindergarten?
The fact I learned to read, write and perform very basic math during kindergarten made the first 3 years of school unbelievably easy for me.