1=.999999...?

[Lohrenswald]

there's infinitely many digits in pi (that isn't just a bunch of zeroes) but you can do arithmetics with that. The same applies with 0,999....
and the square root of 2, for that matter

 

[brennan]

I do lots of mathematics with approximations of pi and root 2. I can never do a calculation using the actual value of pi or root 2 as it doesn't fit on my aging 10 digit calculator. I suspect the same is true for you.

 

[Lohrenswald]

pi*x=7

x=7/pi

I just did it

 

[Arakhor]

Any number that can be expressed as a fraction (i.e. a ratio of any two positive integers) is a rational number, unlike π or √2.

Now, it might seem odd that 0.9 recurring equals 1, but the non-commutability of pq & qp is even odder still and physicists generally accept that oddity as factual.

 

[uppi]

If it is truly a decimal please write it using the digits 1 to ten and a decimal point.

Just because you cannot follow international standards does not mean he should do likewise.

 

[Lohrenswald]

Any number that can be expressed as a fraction (i.e. a ratio of any two positive integers) is a rational number, unlike π or √2.

Now, it might seem odd that 0.9 recurring equals 1, but the non-commutability of pq & qp is even odder still and physicists generally accept that oddity as factual.

that's matrices though. if you have a q matrix and a p matrix, you can see that (most of the time) pq=/=qp

 

[Arakhor]

I never did maths or physics past A-level, I'm afraid, but fractions are fairly basic knowledge. (The HUP is not.)

 

[brennan]

pi*x=7

x=7/pi

I just did it

Invalid. You haven't expressed pi as a decimal. On my calculator pi approximates to 3.141592654, which is not actually=pi.

 

[Birdjaguar]

14 pages and I think I have a headache...

And I hope the three dots don't mean it will last all evening.

 

[Lohrenswald]

I never did maths or physics past A-level, I'm afraid, but fractions are fairly basic knowledge. (The HUP is not.)

My handmousewriting isn't great

Also, I don't now what a-level is :/

Invalid. You haven't expressed pi as a decimal. On my calculator pi approximates to 3.141592654, which is not actually=pi.

Pi=3,1415[AND THEN SOME OTHER DIGITS THAT GO ON INDEFENETELY]
but that doesn't mean I can't use Pi
Your circle has a diameter of 4? then the circumferance is exactly 4*pi

also
3,7=a
a*x=10
x=10/a
how is that invalid?

 

[LucyDuke]

14 pages and I think I have a headache...

And I hope the three dots don't mean it will last all evening.

It's just an approximation of a headache.

This is the most pigeon-chess thread I can remember since ever.

 

[brennan]

It's invalid because I am talking about whether 0.999... or pi are legitimately decimal numbers to which we can apply arithmetic processes like multiplication in exactly the same way we use the number 7. Not whether 4x is 4x - which is algebra not decimal arithmetic.

 

[Lohrenswald]

It's invalid because I am talking about whether 0.999... or pi are legitimately decimal numbers to which we can apply arithmetic processes like multiplication in exactly the same way we use the number 7.

They are

 

[brennan]

Then so is 0.0000

What is 0.0000/4 ?

 

[Birdjaguar]

Thanks Lucy; I'm glad it is not an actual headache. But wait, if 0.99999... = 1, then it isn't an approximation and my headache is real!!! Or have I got that turned around? Uppi, do I have a headache?

 

[Lohrenswald]

0
or 0,00000... if you prefer that

 

[Perfection]

The problem with .999... not being 1 is that it makes using repeating decimals pretty useless (not that they're especially useful)

If .999... isn't 1:
1. What is it?
2. Why should we think it's better to think about it that way?

 

[brennan]

Sorry, should have written that the other way around obviously. What is 4/0.000?

You accept that you cannot divide by zero? That not all identities can have the same operations legitimately applied to them?

 

[Lohrenswald]

I honestly don't remember what an identity is.
if you're asking if 0=0,00000... the answer is yes

 

[Perfection]

I get that 0=0. What's up with the "00000... the answer is yes" clause?