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Math Proof

Does 0.99... = 1?
(No ending time set)
Yes  40%  [ 6 ]
Almost  60%  [ 9 ]

Author Message
Martin

Posted: Tue Sep 09, 2003 11:40 pm   Post subject: Math Proof

Here's the question.
Does 0.999... (repeating) = 1, or is it just really really close?

octopi

Posted: Wed Sep 10, 2003 12:18 am   Post subject: (No subject)

Martin

Posted: Wed Sep 10, 2003 3:24 pm   Post subject: (No subject)

The not posting part was more for people who don't know the answer, so they wouldn't have anyone pushing them in either direction...
Dan

Posted: Wed Sep 10, 2003 4:54 pm   Post subject: (No subject)

wow it is at 50% / 50% right now, i whonder how this one will turn out.
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Martin

Posted: Fri Sep 12, 2003 3:52 pm   Post subject: (No subject)

At the time of writing this the tally was:

6 said Yes
9 said Almost

Well, here's the proof.

Let x = 0.999...repeating
therefor 10x = 9.9999...repeating

10x - x = 9.999..repeating - 0.9999...repeating
therefor 9x = 9, and x = 1.

ooo ahh.
Dan

Posted: Fri Sep 12, 2003 4:12 pm   Post subject: (No subject)

me and octopi talked about this for arouged about this for about 2 hours on msn. Turst me, 0.9999... != 1. To complet that math you have there you HAVE TO round if you dont it will never end, there for 0.9999... rounded is 1. that is why you are geting 1. you cant subtrace 0.9999... from 9.9999... with out rounding, it whould go on forover and you whould never get an aswer.

so to sum that up 0.9999... != 1

now let the flaming start!!!
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octopi

Posted: Fri Sep 12, 2003 4:23 pm   Post subject: (No subject)

Since you let
 code: _ x=0.9
You can subtract x from
 code: _ 9.9
You don't need to round anything.

An easier solution is this:

 code: 1/3 + 2/3 = 3/3   _      _ 0.3  + 0.6  = 1   _ 0.9   = 1

Posted: Fri Sep 12, 2003 5:40 pm   Post subject: (No subject)

no 0.9999 is not = to 1 ... consider this ...

1 / (1 - x)

now do this for x = .9repeating and x = 1

1 / (1 - .9repeating)
1 / 0.0..lots of zeros...1

1 / (1 - 1)
1 / 0 <--- not possible .... ever heard of asymtotes?

some numbers are just really really close to 1 .... but that is all... they are not equal to 1 ... 1.0000000000000000000000000000000 is different than 0.9 repeating

what you are saying is that any number n.9repeating = n+1

SilverSprite

Posted: Fri Sep 12, 2003 6:54 pm   Post subject: (No subject)

0.9 repeating IS equal to 1. Darkness proved it. Another proof is using infinite geometric sums. Also octopi gave another proof. Paddylong, the wrong thing about your 'proof' is that 9 is repeating infinitely. So how can you say ther eis 0.0000000 ... 1 ???? that means you are terminating the string of 0s.

Posted: Fri Sep 12, 2003 10:20 pm   Post subject: (No subject)

it was not meant to be a proof just a consideration

ok, after doing some further reading on the subject, I am wrong and 0.9 repeating does = 1
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