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.999999999999...

Posted: Thu Jan 10, 2008 6:15 pm
by jks
I'm conducting a poll on this for some research I've decided to do. Please answer the poll, and if you want, post what you voted for.

EDIT: For clarity, .999... means .9repeating, or .9 with an infinite number of nines.

Posted: Thu Jan 10, 2008 6:18 pm
by 0m3g4Muff1n987
Your question is does .99999999999 equal 1, right? That's a stupid question. Of course not, at least not technically, but everyone uses common sense and rounds up.

Posted: Thu Jan 10, 2008 6:19 pm
by halo0001
i dont really understand what your asking, but .9(repeat) <> 1 so im going with false

Posted: Thu Jan 10, 2008 6:21 pm
by Aumaan Anubis
Ha jks, trying to fool us all.

Posted: Thu Jan 10, 2008 6:26 pm
by jks
Aumaan Anubis wrote:Ha jks, trying to fool us all. Can I let them in on the secret?
No. >_>

Posted: Thu Jan 10, 2008 6:28 pm
by Tural
1/3 = .3~
2/3 = .6~
3/3 = .9~
3/3 = 1

Posted: Thu Jan 10, 2008 6:29 pm
by jks
Jesus this forum fails, I hate not being mod. Someone fix the poll :|

Posted: Thu Jan 10, 2008 6:31 pm
by 0m3g4Muff1n987
The poll was ok at first, looks like someone fucked it up.

Posted: Thu Jan 10, 2008 6:33 pm
by JacksonCougAr

Code: Select all

x=0.9999999...(infinite)
10x=9.999999...(infinite)
10x=9+0.99999...(infinite)
10x=9+x
9x=9
x=1
Interesting...

[size=0]Fuck off; if this gets deleted you can suck my nuts; fuck you; don't look at this text; I hate being sick; bugger! I'm allowed to post my mind...[/size]

Posted: Thu Jan 10, 2008 6:34 pm
by Aumaan Anubis
JacksonCougAr wrote:

Code: Select all

x=0.9999999...(infinite)
10x=9.999999...(infinite)
10x=9+0.99999...(infinite)
10x=9+x
9x=9
x=1
Interesting...

[size=0]*** off; if this gets deleted you can suck my nuts; *** you; don't look at this text; I hate being sick; bugger! I'm allowed to post my mind...[/size]
I think that that is what would piss him off some more.

Which would of course, amuse me.

Posted: Thu Jan 10, 2008 6:36 pm
by Tural
Every algebraic solution will give you the result that 1 = .9~, because it is true. It's logically inaccurate, but factually based. It's like saying if you walked somewhere, you could never reach the destination, because you could go half the distance, then half of that distance, and so on, infinitely, never reaching the goal, as you are always going half the distance to it. It's a logical idea that is not supported by reality.

Posted: Thu Jan 10, 2008 6:37 pm
by 0m3g4Muff1n987
:shock:





Whoa.





I'm printing and taking in to my math teacher tomorrow.

Posted: Thu Jan 10, 2008 6:43 pm
by shadowkhas
Poll looks fine...(when looking at your post)
Thanks for reminding me about this:

Code: Select all

x=0.9999999...(infinite)
10x=9.999999...(infinite)
10x=9+0.99999...(infinite)
10x=9+x
9x=9
x=1
I'm going to run into my IB Math class and write it on the board for giggles.

/shadowks cuts

Posted: Thu Jan 10, 2008 6:46 pm
by jks
0m3g4Muff1n987 wrote::shock:





Whoa.





I'm printing and taking in to my math teacher tomorrow.
It's nothing that's supposed to be surprising, the two numbers .999... and 1 are exactly equal to one another. .999... is an infinitely repeating decimal expansion of the number 1. And this is completely logically valid, because suppose .999... < 1, then 1 - .999.... > 0, that is to say 1 - .999... is a positive, real number. Then what is 1 - .999...? It doesn't make sense to say that it's .000000(...)001 Because an infinite expansion cannot have a finite ending. The number .999... is actually a condensed infinite geometric series of 9/10^n as n->infinity. And the definition of any infinite geometric series is the smallest possible number that doesn't exceed any of the individual terms, and 1 is the only number that satisfies this condition. Since if you say that .999... != 1, then think of some number that is really, really close to one, but that doesn't equal one. You can't, because it's not possible.

Posted: Thu Jan 10, 2008 6:46 pm
by Aumaan Anubis
I remember that someone actually had it in their signature, here, at HM. Math just completely went down the drain from there for me.

Posted: Thu Jan 10, 2008 6:47 pm
by CptnNsan0
False.

explanation:
(1) .9~ goes on for infinity while as 1 does not.
(2) 1 is an integer, .999999999999999... is not.

Posted: Thu Jan 10, 2008 6:55 pm
by Tural
CptnNsan0 wrote:False.

explanation:
(1) .9~ goes on for infinity while as 1 does not.
(2) 1 is an integer, .999999999999999... is not.
You're using a logical analysis, not a mathematical one. Mathematical equations support it, because it is factually true. While it goes against logic, it isn't really something you can disprove. You're not using evidence to support an analysis, you're just stating comparisons. Analyze the situation, not merely point out stuff within it. You don't have evidence to support your claim, while the other side has a factual set of many equations to back the true claim, that it is equal.

Posted: Thu Jan 10, 2008 6:57 pm
by CptnNsan0
Tural wrote:1/3 = .3~
2/3 = .6~
3/3 = .9~
3/3 = 1
there is no way you can put an infinite decimal into a fraction. It is mathematically impossible.

1/3 does not equal .3~, 1/3 = 1/3

Posted: Thu Jan 10, 2008 6:59 pm
by jks
Tural wrote:
CptnNsan0 wrote:False.

explanation:
(1) .9~ goes on for infinity while as 1 does not.
(2) 1 is an integer, .999999999999999... is not.
You're using a logical analysis, not a mathematical one. Mathematical equations support it, because it is factually true. While it goes against logic, it isn't really something you can disprove.
It also has to do with people not understanding the concept of infinity. And I think it's entirely logical, I came to this conclusion long before anyone told me the answer, because it makes sense.

Posted: Thu Jan 10, 2008 7:08 pm
by Tural
CptnNsan0 wrote:there is no way you can put an infinite decimal into a fraction. It is mathematically impossible.
lol.