tarheel91 said:
Gnizmo said:
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dtewi said:
It is easy. What is infity minus infinity? Zero! What is Infity times one infityth? One! Or alternatively, what is infinty divided by infity? One! What is infinity times 1? Infinty!
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Infinity divided by infinity is undefined in the same way 0/0 is undefined. I am pretty sure Infinity minus infinity is also undefined, but if it isn't then the answer is actually infinity. Infinity * 1/infinity is also undefined. Infinity does not behave like real numbers that you are used to dealing with.
To give you a bit of an idea of how quircky it is I will use the example my first Calculus teacher used. 1 is as close to infinity as 1 trillion, or -1 trillion. Infinity cannot be larger or smaller than what it is. Nothing you do to it can change its value. This is a bit simplified but I don't feel like getting my old text books out to go into greater detail.
On topic: This is actually the subject of some debte amongst mathematicians I seem to recall. There is no decisive arguement for or against it. The only time it is ever going to be relevant though you will be using fractions anyways so it is kind of a moot point. You will never see .3 repeating *3 because it is drilled into your head with unrelenting force that decimals are too inaccurate to use until the absolute end of the equation.
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You're confusing infinity with the limit as something approaches infinity. If it's infinity itself, infinity - infinity is 0. However, if two things are both approaching infinity and you subtract one from the other it's indeterminant.
People need to recognize the difference between limit as something approaches a number and the ACTUAL NUMBER. This is the third time I've explained this on this site.
The limit of something as it approaches 1^Infinity is indeterminate. However, 1^Infinity = 1. See the difference?
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Infinity is not a number! You can't apply normal operations to infinity because it's not a real number, it can only be used when something approaches infinity, you can have x->∞ but not x=∞
