## Question...

### babeasc

Posted 13 May 2007 - 04:39 PM

Right....

we all know that and that undefined and that

so....what does

???

### Pete

Posted 13 May 2007 - 04:49 PM

Black hole. Vortex. Whatever you want to call it. You can't divide by zero, whatever the scenario. is just undefined.

### George

Posted 13 May 2007 - 04:57 PM

is also undefined, since you can't divide by 0.

The reason is that when we write , we want to be the unique solution of the equation .

In the case of (i.e. dividing by zero) the equation is , and if is nonzero, it's impossible to find an which will make that work.

So what if ? Well, then you have to solve - meaning could be anything you like. But then that's not a unique solution, so it goes against what I said above.

So why do we want it to be unique?

Well, what if we just pick one of the possible solutions, and say ?

Then multiplying by 2,

So trying to just use leads us to say , and the universe blows up The same thing would happen if we tried to make any other fixed number. So we just agree not to

### babeasc

Posted 14 May 2007 - 02:34 PM

Thats pretty cool

think it'll come up in the exam lol