#1**+16 **

∞ x ∞ = ∞

∞ + ∞ = ∞

∞ - ∞ = ∞

As you may have noticed, infinity doesn't folllow the "normal" math rules. This because it's a concept rather than a number.

To see the last one above.....note that if I took away all the even integers {an infinite set in themselves} from the set of integers on the number line {another infinite set} , I would have the set of all odd integers left ...... {another infinite set}...!!!!!

CPhill
Feb 24, 2015

#1**+16 **

Best Answer

∞ x ∞ = ∞

∞ + ∞ = ∞

∞ - ∞ = ∞

As you may have noticed, infinity doesn't folllow the "normal" math rules. This because it's a concept rather than a number.

To see the last one above.....note that if I took away all the even integers {an infinite set in themselves} from the set of integers on the number line {another infinite set} , I would have the set of all odd integers left ...... {another infinite set}...!!!!!

CPhill
Feb 24, 2015

#3**+5 **

Imagine the set of all the positive integers. There are an infinite number of them. Take away the infinite number of even integers and you are left with an infinite number of odd integers. So here is an example of where infinity minus infinity equals infinity.

In general, transfinite arithmetic (meaning arithmetic beyond the finite), as it's known, is very complicated and often confounds our intuition!

.

Alan
Feb 24, 2015

#4**0 **

Thanks Alan but you can say that the other way around too

Imagine the set of all even integers. There are an infinite number of them. Take away the infinite number of all integers and you are left with minus an infinite number of odd integers. So here is an example of where infinity minus infinity equals minus infinity.

I am not saying that this is correct only that the logic of you example can be countered.

Melody
Feb 25, 2015