# Mathe questions

BTruesdell07
Is infinity - 1 still infinity. Also if 1\3 = .333... then wouldent 3\3not only = 1 but .999... as well?

## Answers and Replies

Staff Emeritus
Gold Member
I suggest you wander over to the math forum and take a look at the threads answering this question there. The thread requesting an FAQ sticky will be the easiest place to look.

mattmns
I am not sure about the definition of the infinity question. But for the second part: If you have 1/3 = .3333..., then 1/.333333... = 3, so 3/3 = [1/.333333...] / [1/.333333...] which equals 1

ron damon
keep in mind infinity is not a number, but a limit. You can come arbitrarily close to infinity, but you can never reach it.

Staff Emeritus
Gold Member
Much as it pains me to do this, I will have to move this thread from GD to Math.

Staff Emeritus
Gold Member
You can come arbitrarily close to infinity, but you can never reach it.

Actually I don't think you can get close to it. No matter how big a number you choose, infinity it still infinitely "far" away.

Staff Emeritus
Gold Member
BTruesdell07 said:
Is infinity - 1 still infinity.
Yes.
Also if 1\3 = .333... then wouldent 3\3not only = 1 but .999... as well?
Yes again.

ron damon
Integral said:
Actually I don't think you can get close to it. No matter how big a number you choose, infinity it still infinitely "far" away.

your definition is better I like to think of it in the following way:

let's say you have a=x/n . You can choose x to be the greatest number your imagination can muster (thus coming arbitrarily close to infinity). lim of a when n -> infinity will always be 0. So as you said, "infinity it still infinitely "far" away".