Originally posted by muzzleflash

In mathematics, the affinely extended real number system is obtained from the real number system R by adding two elements: +∞ and −∞ (read as positive infinity and negative infinity respectively). The projective extended real number system adds a single object, ∞ (infinity) and makes no distinction between "positive" or "negative" infinity. These new elements are not real numbers. It is useful in describing various limiting behaviors in calculus and mathematical analysis, especially in the theory of measure and integration. The affinely extended real number system is denoted R or [−∞, +∞].

This is different than zero however. So infinity does indeed have polarity while zero has no polarity.

What? Even the article you quoted says it's a single object (bold emphasis mine), then you go and say it has polarity? More like "perceived polarity".

Ants on an ant hill. This can't be solved using the knowledge we have now, we need to go and know MORE! And then we will know the theory for everything.

Originally posted by circlemaker

Originally posted by buddhasystem

Originally posted by circlemaker

Originally posted by muzzleflash
∞ / ∞ = 1

Actually it's both +1 and -1. Infinity, like 0, has no polarity.

If it doesn't, why do we integrate from - to + infinity in some cases?

+/-infinity defines which direction you take to get there. You can go towards infinity in the positive or negative directions but once you're there it's all the same thing.

Not necessarily. If values of a function f(x) have different signs depending on the sign of the argument, one can argue that these are different.