Post me your hardest maths question you know
- Thread starter Jupiter
- Start date
I had a think about this earlier today, and my thinkings on it are as follows.
When you have any decimal (and in your case 0.9 reoccurring)
and it is then multiplied by 10, lets use 0.02 for example
all the numbers shift to the left
so 0.2. Fine I think we all know this.
However in your question.
think of it like this 0.999999999999999999999999 goes on to infinite amounts of decimal places.
so imagine 0.9999 ............. 999{9}(9) [9]
[9] = the infinite decimal number
(9) = the (infinity - 1) decimal number
{9} = the (infinity - 2) decimal number
And so when you multiply by 10
you get:
0.9999 ............ 999{9}(9)[0]
And when you take that from 9.999 reoccurring
you are not left with 9
you are left with:
9.0000 ............... 00{0}(0)[9]
and then when you divide by 9 you are also left with
1.0000 ............... 000{0}(0)[1]
and not 1.
thoughts please?
I understand that if it is reoccurring then it never reaches the end,
and because of this I believe infinity to be a constantly changing number, however this doesn't disprove my point.
If somehow you were to freeze a reoccurring number in an instant of time then you would find the infinite decimal place.
Last edited:
Squaring root 2 is not mathematical trickery
Anything that deals with infinity is, by essentially cheating and not doing the real calculation.
An inexpressible number. That doesn't prove your point. 1/3 is simplified to 0.3r in decimals but that is just that, an approximation. The idea of recurring is to express the fact that we cannot represent the number accurately.
Think of it this way. If 0.9r = 1 then at what point does it equal 1. Recurring relates to the infinite nature of the value recurring, so how can something that by its very nature has no set value equal something that does have a set value.
The only way that 0.9r = 1 is in theoretical maths.
You dispute that root 2 squared is equal to 2?
I think this is where you run into trouble.
Why?
infinity - infinity is 0.
Infinity - infinity + 1 is 1.
I don't see why that's wrong, if you read the rest infinity is never ending and so when I say infinity it is at the end, regardless, and the -1 just means the decimal place before it.
Infinity doesn't work like that.
We can represent it accurately: we invented the 'recurring' notation to represent it. 1/3 === 0.3r. It's by definition of what the 'r' means.
You need to understand that there's many different ways of writing down an expression that equals the same numerical concept. You could choose to rewrite '1' as 'e^(i*pi) + 2', or '2*integral[0->1](x dx)' or '3*1/3' or '0.9r'. They're all equivalent representations of the concept we commonly refer to as '1'. They're not approximations, they're definitively equal.
Seriously, smarter people than us all disagree with you.
Soldato
- Joined
- 12 Apr 2004
- Posts
- 11,788
- Location
- Somewhere
Right, and since this whole discussion doesn't make sense outside the context of "theoretical maths" (which is actually just maths), we can conclude that indeed 0.9r = 1. You can't just say "let's ignore maths" when talking about mathematical problem.
Anyone who disagrees with this is categorically wrong and simply doesn't understand the question. You can disagree with mathematical truths all you want, but that just makes you wrong.
It's essentially the same as arguing that 1.0r does not equal 1 because they're written differently.
Last edited:
How does it work?
it is a theory anyway.
And if infinity is the end, then there has to be a number before it,
it can't just count like:
1, 2, 3, 5 billion.
there has to be a number before it Always, just like there is always a number before any number. (except negative infinity)
Infinity isn't a number. The concept of a 'number before infinity' makes as much sense as the concept of 'Wednesday tasting of bacon'.
Infinity is NOT "the end", it is the absence of an end.
All this talk makes me wish I chose to do Degree level maths,
Doing my A-Levels atm but chose to do Computer Science at university, I love both computing + maths but which to choose was tough.
I guess it was just because I had done maths all my life.
Doing my A-Levels atm but chose to do Computer Science at university, I love both computing + maths but which to choose was tough.
I guess it was just because I had done maths all my life.
Thats a little pedantic. Of course 0.9r is the value 0.9r. But you would never hit the value 1 with 0.9r. You cannot express a number between 0.9r and 1 but I can't see how that is relevant.
That is a little akin to saying "using whole numbers, give me a number between 5 and 6. It can't be done.
The nature of infinity means that it will never hit the next number in the sequence. 0.9r will never be 1 until you get bored and round.
I should have called this thread, 'does 0.9r = 1'
You're welcome
Did you seriously not expect this? surprised i got it in first