# Mathe questions

#### BTruesdell07

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

#### Moonbear

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.

#### Gokul43201

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

#### Integral

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.

#### Gokul43201

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".

#### mathwonk

Homework Helper
is infinity a place? like oz?

#### Jameson

How many of these discussions do we have to have going on? Can't one of the moderators make a sticky and address this subject once and for all? Please.

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