# Poll: 6÷2(1+2)

Discussion in 'General Discussion' started by Barks, 28 Apr 2011.

?

516 vote(s)
68.9%

233 vote(s)
31.1%
1. ordinaryjoe

# Posts: 970

a number divided by 0 is not infinity... It is undefined. Saying a number divided by 0 is infinity implies that 0 times infinity can be whatever number you want.

Anyway, what about -1/0?

2. FoxEye

# Location: Cornwall

0.0r1 doesn't exist. If the 0 is recurring there will never be a 1 at the end of it.

In other words, wherever you chose to put the 1 you are wrong, it should be 0.

3. ordinaryjoe

# Posts: 970

0.0r1 does not exist. You can not have an infinite number of 0s before the 1 - the 1 would not exist, so it's really just 0

4. Vonhelmet

# Location: On the hoods

And yet you can have enough 9s that 0.99r is equal to 1?

Admit the contradiction.

5. Vonhelmet

# Location: On the hoods

The answer is infinity, but it is infinity that is undefined, not the answer.

And -1/0 is -infinity.

And yes, before you ask, infinity can be positive or negative.

6. wmb

# Location: Cumbria

But the equation is not presented in a CONVENTIONAL format, therefore it is AMBIGUOUS. If it was presented in a conventional way, there would be no argument one way or the other.

7. FoxEye

# Location: Cornwall

I believe this is incorrect.

You cannot divide something finite and existing into an infinite number of non-existent parts.

Even if some branch of mathematics says you can, it contradicts reality.

8. Vonhelmet

# Location: On the hoods

In the limit as x->0 that is exactly what you can conceptually do.

9. marc_howarth

# Location: Matlock

Basically if you do multiplying before diving you get one answer and if you do dividing before multiplying you get another answer. The question is ambiguous and really both answers are correct.

10. Castiel

+0.99r

11. mjt

# Posts: 18,597

25 pages? I'm guessing the topic has moved on?

I mean really. The only way to get 1 is 6/(2(1+2))

12. ordinaryjoe

# Posts: 970

There is no contradiction. I don't run out of 9s... there is no limited supply of 9s and there is nothing that comes after it. However, you can't have infinity 0s, then add a 1 on after. If you could, the 1 would have a value of 10^-infinity, which is 0.

You said that all numbers divided by 0 are infinity though, so what happens when you multiply infinity by 0?

13. Killerkebab

# Location: Kent

We don't say 1/0 is infinity, we say 1/0 is undefined

However, if you take 1/x, we say that as x -> 0 (i.e: as x gets smaller and smaller), then 1/x -> infinity.

You read "->" as "tends to"

14. ordinaryjoe

# Posts: 970

Exactly, but x tending to 0 isn't the same as dividing by zero. It is finding out what the number approaches as you get closer and closer to 0.

15. Killerkebab

Yes sir.

16. FoxEye

# Location: Cornwall

In reality, however, you cannot as I said, turn something that exists into something that doesn't exist by dividing it.

Otherwise, you should also be able to do the reverse. Bring something into existence from nothing.

So infinity lots of 0 should create something, no? If it doesn't, then you have a problem! Things can disappear into non-existence and not come back!

17. FoxEye

# Location: Cornwall

I think I understand where you're coming from.

Put it this way, there is no such thing as "an infinitely small number". Any number that is > 0 is finitely small.

1 - 0.9r does not yield an infinitely small number. It yields 0.

0.9r builds the number 1 using an infinite number of building blocks. But it does build the number 1. We have trouble because we only tend to look at the first n building blocks in our minds. And the first n blocks build a number < 1. But there are always more blocks that we can't see.

Given that there is no infinitely small number, 1/x as x->0 does not define or attempt to define 1/0.

18. Vonhelmet

# Location: On the hoods

So you can have infinite 9s but not infinite 0s?

If 0.99r=1 then 0.0r1 must =0 if only because 0.99r+0.0r1 must = 1+0.

19. ordinaryjoe

# Posts: 970

No, that's not what I said... You can have an infinite number of 0s, but you can't then put a 1 on the end of it.

Your 2nd line is right. 0.0r1 is equal to 0.

20. Blue160

# Location: Leatherhead

0.0r1 isn't even a number. The r means the 0's repeat infinitely so writing any number after that is meaningless.