The plane takes off, 0.999... = 1, but what about...

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thesurge

Golden Member
Dec 11, 2004
1,745
0
0
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
<snip>

So basically you are using your idea of what you think math should be, and shunning the use of mathematical theorems :thumbsdown:

So basically you are trying to insult me by making things up (I'm not "shunning the use of mathematical theorems") and not using any support :thumbsdown:

:roll:

I at least expected some more "proof" but I guess there is none, because .999... doesn't equal 1.

Well you made no effort to use rigorous mathematical tools to show why .999... != 1, you just say things like

"Same goes for multiplication. .99999.. times 10 will always be some value less than 10. Yes, it will be so close that it is practically indistinguishable, but it is not 10. "

and

"And subtraction. 1 - 1 = 0. 1 - .99999.... will be some number greater than 0. Yes, there REALLY will be a 1 trailing an infinite amount of zeros. Such a number is so small that it is hard to conceptualize, but that doesn't mean we can just say it is 0 because it's so small. "

So sorry if I believe you are shunning the use of theory when you make baseless claims.

Baseless? What the hell are you smoking? Are you so cought up in believing that they are equal that you can't see the simplicity in how they aren't equal?

Tell me how on earth you can multiply .999... by 10 and NOT get 9.999... That's basic math. You're a fool if you think you need to use "rigorous mathematical tools" to answer something so basic.

Also, tell me how you can divide 10 by 10 and NOT get 1.

Perhaps proofs based on some references from math professors and textbooks might be more convincing:

link

That's the same stuff that's on wiki, and it's still a roundabout way of "proving" it. These ideas are one dimensional, use rounding, and cannot be reversed.

Like I said, just because they can be interchanged in some problems does not make them 100% equal. 1 + .999... will equal 1.999... not 2. That's the most simple, basic math that directly contradicts all other evidence.

So all the math professors are wrong, but you are right?

If two numbers are different, then there must be another number between them, correct? If so, then tell me, what number comes between 0.99999...... and 1?

People also believed the world was flat and they had maps to prove it.

0.000...1 is the difference.

1 comes after 0.999... which makes 1>0.999...
Sorry, but that isn't a real number.
 

jman19

Lifer
Nov 3, 2000
11,225
664
126
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
<snip>

So basically you are using your idea of what you think math should be, and shunning the use of mathematical theorems :thumbsdown:

So basically you are trying to insult me by making things up (I'm not "shunning the use of mathematical theorems") and not using any support :thumbsdown:

:roll:

I at least expected some more "proof" but I guess there is none, because .999... doesn't equal 1.

Well you made no effort to use rigorous mathematical tools to show why .999... != 1, you just say things like

"Same goes for multiplication. .99999.. times 10 will always be some value less than 10. Yes, it will be so close that it is practically indistinguishable, but it is not 10. "

and

"And subtraction. 1 - 1 = 0. 1 - .99999.... will be some number greater than 0. Yes, there REALLY will be a 1 trailing an infinite amount of zeros. Such a number is so small that it is hard to conceptualize, but that doesn't mean we can just say it is 0 because it's so small. "

So sorry if I believe you are shunning the use of theory when you make baseless claims.

Baseless? What the hell are you smoking? Are you so cought up in believing that they are equal that you can't see the simplicity in how they aren't equal?

Tell me how on earth you can multiply .999... by 10 and NOT get 9.999... That's basic math. You're a fool if you think you need to use "rigorous mathematical tools" to answer something so basic.

Also, tell me how you can divide 10 by 10 and NOT get 1.

Perhaps proofs based on some references from math professors and textbooks might be more convincing:

link

That's the same stuff that's on wiki, and it's still a roundabout way of "proving" it. These ideas are one dimensional, use rounding, and cannot be reversed.

Like I said, just because they can be interchanged in some problems does not make them 100% equal. 1 + .999... will equal 1.999... not 2. That's the most simple, basic math that directly contradicts all other evidence.

So all the math professors are wrong, but you are right?

If two numbers are different, then there must be another number between them, correct? If so, then tell me, what number comes between 0.99999...... and 1?

People also believed the world was flat and they had maps to prove it.

0.000...1 is the difference.

1 comes after 0.999... which makes 1>0.999...

Oh great, here comes the bogus "but people once thought that blah blah blah was true." Yes, not all things that we think are true are actually true, but if we just choose to ignore things without trying to discover the truth through rigorous methods then we are just fooling ourselves...
 

jagec

Lifer
Apr 30, 2004
24,442
6
81
Originally posted by: supafly
Originally posted by: jman19

How is stating 1.999 != 2 "the most simple, basic math that directly contradicts all other evidence"? What is your proof, that the numbers "look different"?

They are different. 1.999... will always trail 2.

Your arguments are philosophical, not mathematical.

Mathematically, .9999999... = 1.

Philosophically, I suppose you could state that since they are written differently, they comprise different entities.

But that's like saying that 3 != 3-0, because they're different.

Here's a question for you: is infinity-1 less than infinity?
 

thesurge

Golden Member
Dec 11, 2004
1,745
0
0
Originally posted by: fitzov
Originally posted by: IAteYourMother
Originally posted by: supafly
Originally posted by: randay
No, the plane does not take off.

.99999... doesn't equal 1

yes it does

please, hyperreal numbers, infinitesimals.

Well, the common number system is constricted to the real (Archimedian) field... so there are no nonzero infinitely small numbers.
 

mb

Lifer
Jun 27, 2004
10,233
2
71
Originally posted by: thesurge
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
<snip>

So basically you are using your idea of what you think math should be, and shunning the use of mathematical theorems :thumbsdown:

So basically you are trying to insult me by making things up (I'm not "shunning the use of mathematical theorems") and not using any support :thumbsdown:

:roll:

I at least expected some more "proof" but I guess there is none, because .999... doesn't equal 1.

Well you made no effort to use rigorous mathematical tools to show why .999... != 1, you just say things like

"Same goes for multiplication. .99999.. times 10 will always be some value less than 10. Yes, it will be so close that it is practically indistinguishable, but it is not 10. "

and

"And subtraction. 1 - 1 = 0. 1 - .99999.... will be some number greater than 0. Yes, there REALLY will be a 1 trailing an infinite amount of zeros. Such a number is so small that it is hard to conceptualize, but that doesn't mean we can just say it is 0 because it's so small. "

So sorry if I believe you are shunning the use of theory when you make baseless claims.

Baseless? What the hell are you smoking? Are you so cought up in believing that they are equal that you can't see the simplicity in how they aren't equal?

Tell me how on earth you can multiply .999... by 10 and NOT get 9.999... That's basic math. You're a fool if you think you need to use "rigorous mathematical tools" to answer something so basic.

Also, tell me how you can divide 10 by 10 and NOT get 1.

Perhaps proofs based on some references from math professors and textbooks might be more convincing:

link

That's the same stuff that's on wiki, and it's still a roundabout way of "proving" it. These ideas are one dimensional, use rounding, and cannot be reversed.

Like I said, just because they can be interchanged in some problems does not make them 100% equal. 1 + .999... will equal 1.999... not 2. That's the most simple, basic math that directly contradicts all other evidence.

So all the math professors are wrong, but you are right?

If two numbers are different, then there must be another number between them, correct? If so, then tell me, what number comes between 0.99999...... and 1?

People also believed the world was flat and they had maps to prove it.

0.000...1 is the difference.

1 comes after 0.999... which makes 1>0.999...
Sorry, but that isn't a real number.
You are completely wrong, and you are very close-minded. Please learn some math and come back?

I'm the close minded one because I refuse to believe that two different things are the same because they can end in the same result some of the time?

Right.

I give up. There is no solid proof that they are always equal and I'm not going to waste anymore time arguing about it.
 

Special K

Diamond Member
Jun 18, 2000
7,098
0
76
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
<snip>

So basically you are using your idea of what you think math should be, and shunning the use of mathematical theorems :thumbsdown:

So basically you are trying to insult me by making things up (I'm not "shunning the use of mathematical theorems") and not using any support :thumbsdown:

:roll:

I at least expected some more "proof" but I guess there is none, because .999... doesn't equal 1.

Well you made no effort to use rigorous mathematical tools to show why .999... != 1, you just say things like

"Same goes for multiplication. .99999.. times 10 will always be some value less than 10. Yes, it will be so close that it is practically indistinguishable, but it is not 10. "

and

"And subtraction. 1 - 1 = 0. 1 - .99999.... will be some number greater than 0. Yes, there REALLY will be a 1 trailing an infinite amount of zeros. Such a number is so small that it is hard to conceptualize, but that doesn't mean we can just say it is 0 because it's so small. "

So sorry if I believe you are shunning the use of theory when you make baseless claims.

Baseless? What the hell are you smoking? Are you so cought up in believing that they are equal that you can't see the simplicity in how they aren't equal?

Tell me how on earth you can multiply .999... by 10 and NOT get 9.999... That's basic math. You're a fool if you think you need to use "rigorous mathematical tools" to answer something so basic.

Also, tell me how you can divide 10 by 10 and NOT get 1.

Perhaps proofs based on some references from math professors and textbooks might be more convincing:

link

That's the same stuff that's on wiki, and it's still a roundabout way of "proving" it. These ideas are one dimensional, use rounding, and cannot be reversed.

Like I said, just because they can be interchanged in some problems does not make them 100% equal. 1 + .999... will equal 1.999... not 2. That's the most simple, basic math that directly contradicts all other evidence.

So all the math professors are wrong, but you are right?

If two numbers are different, then there must be another number between them, correct? If so, then tell me, what number comes between 0.99999...... and 1?

People also believed the world was flat and they had maps to prove it.

0.000...1 is the difference.

1 comes after 0.999... which makes 1>0.999...

If you seriously believe that all of the world's mathematicians are wrong about 0.99999.... = 1 (as people were wrong about the world being flat centuries ago), then you need to publish your proof in a mathematical journal ASAP, so other mathematicians can see the error of their ways. The results of your study would be earth-shattering, to say the least.

Also, 0.0000....1 is NOT the difference. You are assuming there is an end to the nines, but there is no end. You are using this:

1 - 0.9999999 = 0.0000001

Whereas we are using this:

1 = 0.9999............

Notice in your case you are imposing an end to the number of nines, whereas in our case we are not. The nines really do go on forever without end.


 

Legendary

Diamond Member
Jan 22, 2002
7,019
1
0
Originally posted by: thesurge
Originally posted by: fitzov
Originally posted by: IAteYourMother
Originally posted by: supafly
Originally posted by: randay
No, the plane does not take off.

.99999... doesn't equal 1

yes it does

please, hyperreal numbers, infinitesimals.

Well, the common number system is constricted to the real (Archimedian) field... so there are no nonzero infinitely small numbers.

I think it's unlikely that supafly was assuming that the Archimedian property did not apply to the number system in question.
 

thesurge

Golden Member
Dec 11, 2004
1,745
0
0
Originally posted by: supafly
Originally posted by: thesurge
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
<snip>

So basically you are using your idea of what you think math should be, and shunning the use of mathematical theorems :thumbsdown:

So basically you are trying to insult me by making things up (I'm not "shunning the use of mathematical theorems") and not using any support :thumbsdown:

:roll:

I at least expected some more "proof" but I guess there is none, because .999... doesn't equal 1.

Well you made no effort to use rigorous mathematical tools to show why .999... != 1, you just say things like

"Same goes for multiplication. .99999.. times 10 will always be some value less than 10. Yes, it will be so close that it is practically indistinguishable, but it is not 10. "

and

"And subtraction. 1 - 1 = 0. 1 - .99999.... will be some number greater than 0. Yes, there REALLY will be a 1 trailing an infinite amount of zeros. Such a number is so small that it is hard to conceptualize, but that doesn't mean we can just say it is 0 because it's so small. "

So sorry if I believe you are shunning the use of theory when you make baseless claims.

Baseless? What the hell are you smoking? Are you so cought up in believing that they are equal that you can't see the simplicity in how they aren't equal?

Tell me how on earth you can multiply .999... by 10 and NOT get 9.999... That's basic math. You're a fool if you think you need to use "rigorous mathematical tools" to answer something so basic.

Also, tell me how you can divide 10 by 10 and NOT get 1.

Perhaps proofs based on some references from math professors and textbooks might be more convincing:

link

That's the same stuff that's on wiki, and it's still a roundabout way of "proving" it. These ideas are one dimensional, use rounding, and cannot be reversed.

Like I said, just because they can be interchanged in some problems does not make them 100% equal. 1 + .999... will equal 1.999... not 2. That's the most simple, basic math that directly contradicts all other evidence.

So all the math professors are wrong, but you are right?

If two numbers are different, then there must be another number between them, correct? If so, then tell me, what number comes between 0.99999...... and 1?

People also believed the world was flat and they had maps to prove it.

0.000...1 is the difference.

1 comes after 0.999... which makes 1>0.999...
Sorry, but that isn't a real number.
You are completely wrong, and you are very close-minded. Please learn some math and come back?

I'm the close minded one because I refuse to believe that two different things are the same because they can end in the same result some of the time?

Right.

I give up. There is no solid proof that they are always equal and I'm not going to waste anymore time arguing about it.

I agree. There is no proof that they are always equal. When working in different (math) fields, lots of things change. But in the real number field, they have been set as always equal.
 

jman19

Lifer
Nov 3, 2000
11,225
664
126
Originally posted by: supafly
Originally posted by: thesurge
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
<snip>

So basically you are using your idea of what you think math should be, and shunning the use of mathematical theorems :thumbsdown:

So basically you are trying to insult me by making things up (I'm not "shunning the use of mathematical theorems") and not using any support :thumbsdown:

:roll:

I at least expected some more "proof" but I guess there is none, because .999... doesn't equal 1.

Well you made no effort to use rigorous mathematical tools to show why .999... != 1, you just say things like

"Same goes for multiplication. .99999.. times 10 will always be some value less than 10. Yes, it will be so close that it is practically indistinguishable, but it is not 10. "

and

"And subtraction. 1 - 1 = 0. 1 - .99999.... will be some number greater than 0. Yes, there REALLY will be a 1 trailing an infinite amount of zeros. Such a number is so small that it is hard to conceptualize, but that doesn't mean we can just say it is 0 because it's so small. "

So sorry if I believe you are shunning the use of theory when you make baseless claims.

Baseless? What the hell are you smoking? Are you so cought up in believing that they are equal that you can't see the simplicity in how they aren't equal?

Tell me how on earth you can multiply .999... by 10 and NOT get 9.999... That's basic math. You're a fool if you think you need to use "rigorous mathematical tools" to answer something so basic.

Also, tell me how you can divide 10 by 10 and NOT get 1.

Perhaps proofs based on some references from math professors and textbooks might be more convincing:

link

That's the same stuff that's on wiki, and it's still a roundabout way of "proving" it. These ideas are one dimensional, use rounding, and cannot be reversed.

Like I said, just because they can be interchanged in some problems does not make them 100% equal. 1 + .999... will equal 1.999... not 2. That's the most simple, basic math that directly contradicts all other evidence.

So all the math professors are wrong, but you are right?

If two numbers are different, then there must be another number between them, correct? If so, then tell me, what number comes between 0.99999...... and 1?

People also believed the world was flat and they had maps to prove it.

0.000...1 is the difference.

1 comes after 0.999... which makes 1>0.999...
Sorry, but that isn't a real number.
You are completely wrong, and you are very close-minded. Please learn some math and come back?

I'm the close minded one because I refuse to believe that two different things are the same because they can end in the same result some of the time?

Right.

I give up. There is no solid proof that they are always equal and I'm not going to waste anymore time arguing about it.

How is there no solid proof?

Let's begin with this...

Infinite Geometric Series ftw.

.9999....=sigma(9/(10^k),k,1,oo)=\frac{(9/10)}{1-1/10}=1

Why is this wrong?
 

KingGheedora

Diamond Member
Jun 24, 2006
3,248
1
81
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: Special K
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
Originally posted by: jman19
Originally posted by: supafly
<snip>

So basically you are using your idea of what you think math should be, and shunning the use of mathematical theorems :thumbsdown:

So basically you are trying to insult me by making things up (I'm not "shunning the use of mathematical theorems") and not using any support :thumbsdown:

:roll:

I at least expected some more "proof" but I guess there is none, because .999... doesn't equal 1.

Well you made no effort to use rigorous mathematical tools to show why .999... != 1, you just say things like

"Same goes for multiplication. .99999.. times 10 will always be some value less than 10. Yes, it will be so close that it is practically indistinguishable, but it is not 10. "

and

"And subtraction. 1 - 1 = 0. 1 - .99999.... will be some number greater than 0. Yes, there REALLY will be a 1 trailing an infinite amount of zeros. Such a number is so small that it is hard to conceptualize, but that doesn't mean we can just say it is 0 because it's so small. "

So sorry if I believe you are shunning the use of theory when you make baseless claims.

Baseless? What the hell are you smoking? Are you so cought up in believing that they are equal that you can't see the simplicity in how they aren't equal?

Tell me how on earth you can multiply .999... by 10 and NOT get 9.999... That's basic math. You're a fool if you think you need to use "rigorous mathematical tools" to answer something so basic.

Also, tell me how you can divide 10 by 10 and NOT get 1.

Perhaps proofs based on some references from math professors and textbooks might be more convincing:

link

That's the same stuff that's on wiki, and it's still a roundabout way of "proving" it. These ideas are one dimensional, use rounding, and cannot be reversed.

Like I said, just because they can be interchanged in some problems does not make them 100% equal. 1 + .999... will equal 1.999... not 2. That's the most simple, basic math that directly contradicts all other evidence.

So all the math professors are wrong, but you are right?

If two numbers are different, then there must be another number between them, correct? If so, then tell me, what number comes between 0.99999...... and 1?

People also believed the world was flat and they had maps to prove it.

0.000...1 is the difference.

1 comes after 0.999... which makes 1>0.999...

The same logic that you discredit for the informal proof that 1 = 0.999... is the same logic you are using in that argument...

By taking 1>0.999... as a priori knowledge, you are assuming that 1 != 0.999..., and therefore using the concept you are trying to prove to prove itself.

There is no 1 after 0.999... By the very definition of 0.999..., there are nines and nines and nines, and nothing else, on into infinity. That's what you don't seem to understand. You can't stop the series at some arbitrary point and say "now put a 1 at the end of this". As soon as you stop it, it is no longer 0.999..., it becomes whatever number you decided to use to illustrate your (invalid) point.
 

Tiamat

Lifer
Nov 25, 2003
14,068
5
71
hah, thats what happens with any sort of .999... = 1 threads.

At least I answered your OP riddle :p
 

tikwanleap

Senior member
Oct 9, 1999
922
0
0
Originally posted by: supafly

<snip of quote fest>

People also believed the world was flat and they had maps to prove it.

0.000...1 is the difference.

1 comes after 0.999... which makes 1>0.999...

Hey supafly...

How would you feel if I told you that 0.000...1 is actually zero? :p

If the number 0.000...1 equals zero then it also means that .999 repeating does equal one. :laugh:


Let's think about what 0.000...1 really is.

First think about 0.1. It is 1/10.

Next 0.01. That's 1/100.

Ok how about 0.001? 1/1000

See a pattern?

So 0.000...1 is the same as 1/(some insanely huge number) or 1/infinity.

You have to trust me on this one, but 1/infinity is equal to zero.

So 0.000...1 equals zero!!!

This means that the difference between 0.999... and 1 is zero, and therefore 0.999... must equal 1.
 

fitzov

Platinum Member
Jan 3, 2004
2,477
0
0
Originally posted by: thesurge
Originally posted by: fitzov
Originally posted by: IAteYourMother
Originally posted by: supafly
Originally posted by: randay
No, the plane does not take off.

.99999... doesn't equal 1

yes it does

please, hyperreal numbers, infinitesimals.

Well, the common number system is constricted to the real (Archimedian) field... so there are no nonzero infinitely small numbers.

Hyperreal numbers are real numbers. Newton and Leibniz used infinitesimals, some mathematicians prefer their use to limits in the Calculus, and they often provide a simpler analysis to Calc problems. But even if you don't use them, the result does not make 0.999... equal to 1.

Here is a quote from a common Calculus book:

"The limit of an infinite series is sometimes called its 'sum at infinity,' but of course this is not a sum in the usual arithmetical sense when the number of terms is finite. You can't obtain the "sum" of an infinite series by adding because the number of terms to be added is infinite. When we speak of the "sum" of an infinite series, this is just a short way of naming its limit...

So what you're really saying when you say 0.999... = 1, is that the limit of the infinite series (denoted by '...')0.999 is 1. This is, strictly speaking, not the same thing as equality.

 

khas

Member
Sep 23, 2006
73
0
61
Hyperreal numbers are real numbers. Newton and Leibniz used infinitesimals, some mathematicians prefer their use to limits in the Calculus, and they often provide a simpler analysis to Calc problems. But even if you don't use them, the result does not make 0.999... equal to 1.

Here is a quote from a common Calculus book:

"The limit of an infinite series is sometimes called its 'sum at infinity,' but of course this is not a sum in the usual arithmetical sense when the number of terms is finite. You can't obtain the "sum" of an infinite series by adding because the number of terms to be added is infinite. When we speak of the "sum" of an infinite series, this is just a short way of naming its limit...

So what you're really saying when you say 0.999... = 1, is that the limit of the infinite series (denoted by '...')0.999 is 1. This is, strictly speaking, not the same thing as equality.

I believe that saying the Limit of ___ is 1 is the same as saying the Limit of ___ = 1. ('is' == 'equals')

Correct me if I'm wrong, but what you just quoted there indeed says that .999... is equal to 1.

I believe that book is saying that the notation .999...(repeating) is not a number but a representation of a Limit. This limit, as we've all read about to death, equals 1.

Or perhaps what you're saying is that the Limit does not equal 1, but converges at 1 (is that the proper term?). And that convergence is not the same as equality. I can't vouch for that one... might have to ask a mathematician.
 

thesurge

Golden Member
Dec 11, 2004
1,745
0
0
Originally posted by: fitzov
Originally posted by: thesurge
Originally posted by: fitzov
Originally posted by: IAteYourMother
Originally posted by: supafly
Originally posted by: randay
No, the plane does not take off.

.99999... doesn't equal 1

yes it does

please, hyperreal numbers, infinitesimals.

Well, the common number system is constricted to the real (Archimedian) field... so there are no nonzero infinitely small numbers.

Hyperreal numbers are real numbers. Newton and Leibniz used infinitesimals, some mathematicians prefer their use to limits in the Calculus, and they often provide a simpler analysis to Calc problems. But even if you don't use them, the result does not make 0.999... equal to 1.

Here is a quote from a common Calculus book:

"The limit of an infinite series is sometimes called its 'sum at infinity,' but of course this is not a sum in the usual arithmetical sense when the number of terms is finite. You can't obtain the "sum" of an infinite series by adding because the number of terms to be added is infinite. When we speak of the "sum" of an infinite series, this is just a short way of naming its limit...

So what you're really saying when you say 0.999... = 1, is that the limit of the infinite series (denoted by '...')0.999 is 1. This is, strictly speaking, not the same thing as equality.
Hmm... The number '.999...' itself is defined as a limit (in the reals), so would the evaluation of it (using its own limit) not be the same as its equality?

"Intuition and ambiguous teaching lead students to think of the limit of a sequence as a kind of infinite process rather than a fixed value, since the sequence never reaches its limit. Those who accept the difference between a sequence of numbers and its limit might read "0.999?" as meaning the former rather than the latter."
-Tall and Schwarzenberger p.6; Tall 2001 p.221


For the infinitesimal stuff... see this property of the real field:
http://en.wikipedia.org/wiki/Archimedean_property

But hey, you may be right... I know very little math and I haven't studied the exact definition of 'equality' yet...

 

Injury

Lifer
Jul 19, 2004
13,066
2
81
Originally posted by: BrownTown
.99999 DOES EQUAL 1 (this is not up for debate, if you don't understand why this is true thats your own fault, but this is a fact in mathematics)

The only way .999 repeating can equal 1 is if you truncate the number of 9's and round barely.
 

Horus

Platinum Member
Dec 27, 2003
2,838
1
0
Originally posted by: SoulAssassin
mythbusters should do the plane on a runway thing

IT DOES NOT TAKE OFF. The aircraft has no LIFT flowing over the wings, and therefore cannot take off!
 

randay

Lifer
May 30, 2006
11,018
216
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Originally posted by: Horus
Originally posted by: SoulAssassin
mythbusters should do the plane on a runway thing

IT DOES NOT TAKE OFF. The aircraft has no LIFT flowing over the wings, and therefore cannot take off!

:laugh: whether you are serious or joking it doesnt matter, just :laugh:
 

fitzov

Platinum Member
Jan 3, 2004
2,477
0
0
Originally posted by: khas
Hyperreal numbers are real numbers. Newton and Leibniz used infinitesimals, some mathematicians prefer their use to limits in the Calculus, and they often provide a simpler analysis to Calc problems. But even if you don't use them, the result does not make 0.999... equal to 1.

Here is a quote from a common Calculus book:

"The limit of an infinite series is sometimes called its 'sum at infinity,' but of course this is not a sum in the usual arithmetical sense when the number of terms is finite. You can't obtain the "sum" of an infinite series by adding because the number of terms to be added is infinite. When we speak of the "sum" of an infinite series, this is just a short way of naming its limit...

So what you're really saying when you say 0.999... = 1, is that the limit of the infinite series (denoted by '...')0.999 is 1. This is, strictly speaking, not the same thing as equality.

I believe that saying the Limit of ___ is 1 is the same as saying the Limit of ___ = 1. ('is' == 'equals')

Correct me if I'm wrong, but what you just quoted there indeed says that .999... is equal to 1.

I believe that book is saying that the notation .999...(repeating) is not a number but a representation of a Limit. This limit, as we've all read about to death, equals 1.

Or perhaps what you're saying is that the Limit does not equal 1, but converges at 1 (is that the proper term?). And that convergence is not the same as equality. I can't vouch for that one... might have to ask a mathematician.

It's the limit of the function that equals 1, not the function itself.

In other words 'f(x) = y' is not the same as 'lim f(x) as "the counter" approaches infinity =y'

Read this:

http://www.math.wisc.edu/~keisler/chapter_9.pdf