So equivalence equals equality? You just blew my mind. I suppose mathematically that would be written as. ===Lukeje said:Saying that a is equivalent to b means that a=b if and only if b=a. Equivalence thus implies equality).
So equivalence equals equality? You just blew my mind. I suppose mathematically that would be written as. ===Lukeje said:Saying that a is equivalent to b means that a=b if and only if b=a. Equivalence thus implies equality).
If that was true then you could do this:Shadowkire said:.000_1 = 0
But .000_1 is such a messy way of typing that number, so let us clean it up. It basically means an infinitely small number so using & as a symbol for an infinitely large number:
1/& = 0
Now we all know any number multiplied by 0 equals 0, even an infinitely large number.
It's not wrong, it's just not a proof of .999... = 1. That doesn't mean that no proofs of .999... = 1 exist. Several do exist.irishda said:Regardless, the math for proving .999r=1 is still wrong, considering the equations are just proving that x=x
Nah, it would be ===>= (using => for implies and == for equivalence).OlasDAlmighty said:So equivalence equals equality? You just blew my mind. I suppose mathematically that would be written as. ===Lukeje said:Saying that a is equivalent to b means that a=b if and only if b=a. Equivalence thus implies equality).
Sorry, you are correct, so let me redo that:cookyy2k said:An infinitely large number multiplied by 0 is NOT 0, it is undefined.
That's the point isn't it? They are one and the same number.irishda said:Regardless, the math for proving .999r=1 is still wrong, considering the equations are just proving that x=x
How did 0.999_ suddenly became 0.999_9 ?Shadowkire said:Sorry, you are correct, so let me redo that:cookyy2k said:An infinitely large number multiplied by 0 is NOT 0, it is undefined.
.000_1 = 0
Subtracting or adding 0 from/with any number equals that number
So .999_ - .000_1 must equal 1 or .999_...
.999_8 So .999_8 = 1
.999_8 - .000_1 = .999_7
Let us try this an infinite number of times, checking our answers along the way. Let us try it with addition as well. Every time it shows 1 equals a new number.
In fact, adding or subracting .000_1 an infinite amount of times will eventually return every single number as equaling 1. Which is false.
Except that we are trying to prove x=x, that's the point of the exercise.irishda said:Regardless, the math for proving .999r=1 is still wrong, considering the equations are just proving that x=x
That was my point, until someone pointed out infinity doesn't work with normal math, that if 1 = .999_ then it follows that 1 = 0. I used that to point out the ridiculousness of the OP's proof.oktalist said:If that was true then you could do this:Shadowkire said:.000_1 = 0
But .000_1 is such a messy way of typing that number, so let us clean it up. It basically means an infinitely small number so using & as a symbol for an infinitely large number:
1/& = 0
Now we all know any number multiplied by 0 equals 0, even an infinitely large number.
1/& = 0
Multiply both sides by &
1 = 0
the underscore is my way of saying "repeating", the number after the underscore is my way of saying "at the end of this infinitely repeating number is an 8, or a 7."Makhiel said:How did 0.999_ suddenly became 0.999_9 ?Shadowkire said:Sorry, you are correct, so let me redo that:cookyy2k said:An infinitely large number multiplied by 0 is NOT 0, it is undefined.
.000_1 = 0
Subtracting or adding 0 from/with any number equals that number
So .999_ - .000_1 must equal 1 or .999_...
.999_8 So .999_8 = 1
.999_8 - .000_1 = .999_7
Let us try this an infinite number of times, checking our answers along the way. Let us try it with addition as well. Every time it shows 1 equals a new number.
In fact, adding or subracting .000_1 an infinite amount of times will eventually return every single number as equaling 1. Which is false.
The OP's proof is not a good one, I feel it over complicates it, but one can replicate the results using other, much simpler processes.Shadowkire said:That was my point, until someone pointed out infinity doesn't work with normal math, that if 1 = .999_ then it follows that 1 = 0. I used that to point out the ridiculousness of the OP's proof.oktalist said:If that was true then you could do this:Shadowkire said:.000_1 = 0
But .000_1 is such a messy way of typing that number, so let us clean it up. It basically means an infinitely small number so using & as a symbol for an infinitely large number:
1/& = 0
Now we all know any number multiplied by 0 equals 0, even an infinitely large number.
1/& = 0
Multiply both sides by &
1 = 0
I didn't ask what the underscore meant.Shadowkire said:the underscore is my way of saying "repeating", the number after the underscore is my way of saying "at the end of this infinitely repeating number is an 8, or a 7."
Yes I am aware of how odd it is to try an place a number at the end of an infinite.
It's not just odd, it's completely backwards and meaningless.Shadowkire said:Yes I am aware of how odd it is to try an place a number at the end of an infinite.
Wyes said:Except that we are trying to prove x=x, that's the point of the exercise.
0.999... = 1 is a widely accepted mathematical fact. This is not a bunch of people on a forum going 'Look I'm a genius and I proved this new thing', it's a guy going 'Hey I learnt this and thought it was super cool it (which it is) but I overestimated its significance'
Personally I'm a much bigger fan of the simpler approach (which has been shown here before).
1/3 = 0.333...
1/3 * 3 = 0.333... * 3
3/3 = 0.999...
1 = 0.999...
It's really just as simple as that.
Now, I'm not going to go and call anyone an idiot for disbelieving this, it doesn't seem right, in a way it's nice to see so many people try to apply critical thinking to the problem, and not just assuming its correct (though let's face it, that's really coming about because they heard it from a guy on the internet).
The OP's original equations don't show .999r=1 because the math is off. It's like that riddle about the waiter splitting a $30 bill three ways and losing $3. The logic is just slightly off.Makhiel said:That's the point isn't it? They are one and the same number.![]()
But 8.99r is 9.irishda said:The assumption is made in the original equation that 9x=9, but 9(.999r) is only 8.99r.
Once again, this is dealing with infinitesimals, which cannot be measured, so there's bound to be stupid little errors like that when you try to measure them (or leave out measuring them when they're supposed to be included, as the case may be).ACman said:Ummmmmmmmmmmmm.
1/3 = 0.3 rep
2/3 = 0.6 rep
3/3 = ?
irishda said:Either way you don't get .999r=1
As for the fractions, I understand you need to know fractals in order to refute that one, but it's still refutable.
I must I must double post; 0.333... and their ilk are not approximations. If you try to take them to some amount of decimal places, then yes, they are approximations, but they go on to infinity! There is no 'error'.Truth Cake said:Once again, this is dealing with infinitesimals, which cannot be measured, so there's bound to be stupid little errors like that when you try to measure them (or leave out measuring them when they're supposed to be included, as the case may be).
I'll be blunt- 1/3 does not QUITE equal .333... (and by proxy, 2/3 doesn't quite equal .666...), that's just as close as we can come to measuring it since we can't write something to the infinity decimal place. (unless you've found a way that I don't know about, which no offense, but I highly doubt)
And obviously 3 divided by 3 is 1, plain and simple.
Again, only if you already believe that .999r=1. But that's changing the math to suit your belief. It doesn't change the fact that 9x=8.999r. If you divide that by 9, then oh look at that, you get x=.99r. Not x=1Makhiel said:But 8.99r is 9.irishda said:The assumption is made in the original equation that 9x=9, but 9(.999r) is only 8.99r.![]()
You could've just edited your first pose to include the quote and response...Wyes said:I must I must double post; 0.333... and their ilk are not approximations. If you try to take them to some amount of decimal places, then yes, they are approximations, but they go on to infinity! There is no 'error'.
It's got nothing to do with measurement, and there is no infinitesimal involved.Truth Cake said:Once again, this is dealing with infinitesimals, which cannot be measured
We have found a way to write infinity decimal places. That's what the ... on the end of .333... means.I'll be blunt- 1/3 does not QUITE equal .333... (and by proxy, 2/3 doesn't quite equal .666...), that's just as close as we can come to measuring it since we can't write something to the infinity decimal place. (unless you've found a way that I don't know about, which no offense, but I highly doubt)
This seems to be the root of your confusion, your assumption that infinite decimals are just approximations.The_root_of_all_evil said:But that confounds the problem because the only way of creating a recurring decimal is the decimal approximation of a fraction.