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#931
Jul 7 2010 02:16pm
there's 2 that I know of.

One is

if x=.999....
then 10x=9.999....
therefore since x=.999 you can make that 10x=9+x
10x-x=9
9x=9
x=1

OR

you can use a geometric series to prove:

So your series is .9 + .09 + .009 + ...
So this is a geometric series with a ratio of 1/10 since (.9)(1/10)=.09 And so on..

Since this is true, the formula for the sum of any series is an/(1-r) where r is the ratio

an is the first term so

(9/10)/(1-1/10)=(9/10)/(9/10)=1

True story folks

This post was edited by PraizeAllah on Jul 7 2010 02:16pm
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#932
Jul 7 2010 07:18pm
Quote (PraizeAllah @ Jul 8 2010 06:16am)
there's 2 that I know of.

One is

if x=.999....
then 10x=9.999....
therefore since x=.999 you can make that 10x=9+x
10x-x=9
9x=9
x=1

OR

you can use a geometric series to prove:

So your series is .9 + .09 + .009 + ...
So this is a geometric series with a ratio of 1/10 since (.9)(1/10)=.09 And so on..

Since this is true, the formula for the sum of any series is an/(1-r) where r is the ratio

an is the first term so

(9/10)/(1-1/10)=(9/10)/(9/10)=1

True story folks


Dumbass, that has already been posted. You disappoint all users viewing this topic from the past, present and future.
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#933
Jul 7 2010 07:22pm
Quote (PraizeAllah @ Jul 7 2010 03:16pm)
there's 2 that I know of.

One is

if x=.999....
then 10x=9.999....
therefore since x=.999 you can make that 10x=9+x
10x-x=9
9x=9
x=1

OR

you can use a geometric series to prove:

So your series is .9 + .09 + .009 + ...
So this is a geometric series with a ratio of 1/10 since (.9)(1/10)=.09 And so on..

Since this is true, the formula for the sum of any series is an/(1-r) where r is the ratio

an is the first term so

(9/10)/(1-1/10)=(9/10)/(9/10)=1

True story folks


x=1 just proves that 10x = 9+x

not that x=1 while = .999

when did u guys not understand this?
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#934
Jul 7 2010 08:18pm
Quote (Magikarpet @ Jul 7 2010 09:22pm)
x=1 just proves that 10x = 9+x

not that x=1 while = .999

when did u guys not understand this?


Do you not understand how a mathematical proof works?
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#935
Jul 7 2010 08:24pm
Quote (Sioux @ Jul 7 2010 09:18pm)
Do you not understand how a mathematical proof works?

u think .999 = 1

idiot!

This post was edited by Magikarpet on Jul 7 2010 08:28pm
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#936
Jul 7 2010 08:32pm
Quote (shem @ Jul 7 2010 06:32pm)
Of course you can! But at such an age one cannot claim to have mathematical knowledge that allows a generalisation of that calibre. You see, I also read you're from Vic. Now since you're in year 10(?) or thereabouts, how can you say that you have more intelligence then someone, say, in their third year of Uni?

You haven't even taken Methods or Specialist Maths yet!


Actually yes I have because I am accelerating in year 11 subjects.
And the fact that I chose to complete school and finish year 10, 11 and 12 doesn't make me any worse than someone who decided to drop out of school and start doing a TAFE/University course.
What you are saying is that you think that every year 11 is smarter than a year 10 and every year 10 is smarter than a year 9 student.
I'm sorry, but it just doesn't work that way.

EDIT: Btw, you must go to a pretty shit university if they tell you there that 0.999... does not equal 1.

This post was edited by Hammer_Hdin on Jul 7 2010 08:32pm
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#937
Jul 7 2010 08:33pm
Quote (Magikarpet @ Jul 8 2010 11:22am)
x=1 just proves that 10x = 9+x

not that x=1 while = .999

when did u guys not understand this?


Ok, let's say that 10x = 9+ x
Now, take away 9 from both sides and that leaves you with:
x=1
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#938
Jul 7 2010 08:34pm
Quote (Hammer_Hdin @ Jul 7 2010 09:33pm)
Ok, let's say that 10x = 9+ x
Now, take away 9 from both sides and that leaves you with:
x=1


yes x=1

.999 does not
for .999
oh and by the way 10x = 9+x is false
considering it would 9.99=9.999
so its always 1 away in the infinite spectrum, since .999... will always be infinitly away from 1

u must be extremely mad

This post was edited by Magikarpet on Jul 7 2010 08:45pm
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#939
Jul 7 2010 08:44pm
Quote (Magikarpet @ Jul 8 2010 12:34pm)
yes x=1

.999 does not


The first step stated than x = 0.999...
The last step stated than x = 1
Therefore, 1 = 0.999...
Learn to substitute please.
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#940
Jul 7 2010 08:45pm
Quote (Hammer_Hdin @ Jul 7 2010 09:44pm)
The first step stated than x = 0.999...
The last step stated than x = 1
Therefore, 1 = 0.999...
Learn to substitute please.


no

because 10x = 9+x
is 9.99=9.999

if ur going to use infinite in an equation
have fun doing that equation for the rest of ur life w/o ever finding a solution

This post was edited by Magikarpet on Jul 7 2010 08:47pm
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