+0

# inf+(-inf) = ?

0
350
13

inf+(-inf)

Guest May 10, 2014

#3
+330
+17

I would say it is "aleph null" or undefined, unless the infinities are explicitly defined as countable, but I'll ask Georg Cantor.

DavidQD  May 10, 2014
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#1
0

lol idk idc

Guest May 10, 2014
#2
+91454
+11

Well, it is probably zero but (It is not)  someone else should give their thoughts on the matter.

DavidQD you are on the forum - what do you think?

Melody  May 10, 2014
#3
+330
+17

I would say it is "aleph null" or undefined, unless the infinities are explicitly defined as countable, but I'll ask Georg Cantor.

DavidQD  May 10, 2014
#4
+81022
+8

On first blush, we might consider the answer to be "0.'

But, it's not.....

Consider the set of integers on the number line. You will agree - I hope - that this set is infinite. Now, consider the set of even integers on the number line. Again, we'll consider this set to be infinite, too.

So, subtracting the second "infinity" from the first "infinity," we end up with another infinite set - the set of all odd integers !!

Thus,   ∞ - ∞ = ∞

Also, notice another odd property......I've divided one set in half and gotten another infinite set. Thus....

∞ / 2  = ∞

One more interesting idea, and then I'll shut up.  Which "infinity" is "greater?"  The set of all positive integers, or the set of all positive even integers??

Note, that I can "count" each positive even integer.....For example, 2 is the first one, 4 is the second one, etc. Thus, I can put each positive even integer into a one-to-one correspondence with a "counting" number. And since I can do so, then the set of positive even integers must be just as large as the set of all the positive integers !!!

CPhill  May 10, 2014
#5
+7
+11

101 thanks

anana  May 10, 2014
#6
+91454
+8

This is who David is referring to.

http://en.wikipedia.org/wiki/Georg_Cantor

Melody  May 10, 2014
#7
+330
+12

There is a post on here titled

A Method of Statistical Inference on Two-dimensional Object Ratios

It broaches infinities – it is a brilliant peace of work.

DavidQD  May 10, 2014
#8
+91454
+3

Thanks Chris and David and thank you Anana for you good manners.

If you give the answers you like a thumbs up you can give them lots of points!  You have the POWER!

Melody  May 10, 2014
#9
+91454
+3

You know Chris, you never really did give an answer.

Melody  May 10, 2014
#10
+81022
+8

It's right there in my eighth "sentence".......

"Thus,   ∞ - ∞ = ∞"..........

CPhill  May 10, 2014
#11
+91454
0

Okay Chris.

I thought you might be able to argue different cases to get different answers and hence end up with undefined.

Thank you.

Melody  May 10, 2014
#12
+81022
0

I can only do that with my "normal" answers........LOL!!!

CPhill  May 10, 2014
#13
+91454
0

CONGRATULATIONS CHRIS!

YOU HAVE THE POWER!!!

Melody  May 10, 2014

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