Maths query

[MyUserName]

You can divide 0

Can you? Or do you mean that you can but the answer is just infinity?

[scooterscot]

You can divide 0

Dividing is a verb.

If I'm dividing with '0' I'm not really dividing am I? So in fact 'something' divided by '0' is in fact the same as doing nothing.

I've just solved an infinite number of equations by dividing by them by nothing.

[scooterscot]

If this thread is going to turn into users attempting to attribute infinity with scale, I'm out.

[MyUserName]

We were taught that dividing x by y was just working out how many times y needed to be taken away from x to equal 0.

Hence 20 / 4 = 5 means 4 needs to be taken away from 20 5 times to be 0.

Therefore x/0 is infinite as it does not matter how many times you take 0 away from x it will never equal 0.

[Bunk]

Can you? Or do you mean that you can but the answer is just infinity?

The answer is 0, unless you're trying to divide by 0.

[Project Monkey]

This is similar to the square of -1 question. That is, it can't be expressed as a whole number so is replaced in formulas by a representation.

[Project Monkey]

We were taught that dividing x by y was just working out how many times y needed to be taken away from x to equal 0.

Hence 20 / 4 = 5 means 4 needs to be taken away from 20 5 times to be 0.

Therefore x/0 is infinite as it does not matter how many times you take 0 away from x it will never equal 0.

This is incorrect. There is no answer because there is, in effect, no question. Asking: "what is x divided by zero?", is the same as "what is x divided by...?"

In practicle terms, it the same as asking someone: "how long is...?". You haven't finished the question so there is no answer (and it certainly isn't infinity).

[jamesbrown]

Listen, this is a well-worn problem with a simple answer. The answer is: yes, they are equal when using real numbers, due to the rules of the real number system. Knock yourself out:

0.999... - Wikipedia, the free encyclopedia...

[SpontaneousOrder]

0.999 recurring is an expression which is impossible to evaluate. The closest approximation which is possible to evaluate is 1. That doesn't mean they are the same. Is it as good as 1? yes. Is it equal to one? clearly not as it's impossible to evaluate.

[original PM]

As others have said it is a good apprximation to 1 but it does not equal 1.

Each time you add a 9 to your 0.999999 you are getting a better approximation to 1 - even if you went to 0.9999 ... and carry for a couple of million 9's you will just be getting a better and better approximation to 1 but it will never equal 1.

- If you did a graph of it the lines would never meet but they would get so close that you could not tell the difference.