Quote (CPK001 @ May 19 2010 04:00am)
Just that 1/7 makes it a lot quicker than to write it down the other way?
Sure, you can think of it like that. But there's more to it than just that. There's a matter of precision. If you're working on a problem and you come across the quantity 1/2, you can surely write it as 0.5 - not just because it's short/easy to write down, but also because there's no confusion about what you're talking about. 1/2 is 0.5. ANY decimal representation that you write down of 1/7 will be an estimation: 0.1428 is very close to 1/7, but they aren't the same. So if you want to be precise, use 1/7.
Quote (Yankzfan @ May 19 2010 04:35am)
Yes it does. .999999.... going to infinity gets so infinately close to one that it is, for all purposes, one. I could post some proofs but honestly, I dun fee like it lol
There's no such thing as "infinitely close" in the real numbers (this is a consequence of the Archimedean property). So no, .999... is not infinitely close to 1. It IS one.