Wat is infinity/0  &  infinityXzero?
490253
infinity/0 is infinity.  If you have any function f(x) and g(x) where f(x) goes to infinity as x -> k and g(x) goes to zero as x -> k, then 1/g(x) goes to infinity as x -> k, so\n\nf(x)*(1/g(x)) -> infinity as x -> k.\n\ninfinity*zero depends. If you look at 1/x and x^2, then as x -> 0, 1/x -> infinity and x^2 -> 0, but\n\n(1/x)*(x^2) = x, so its limit is 0 as x -> 0.\n\nIf you look at 1/x^2 and x, then as x -> 0, 1/x^2 -> infinity and x -> 0, but\n\n(1/x^2)*(x) = 1/x, so its limit is infinity as x -> 0.
1042350
8 turned sideways means infinity, a never-ending loop.  So 88 is just double infinity
187658
it's defined \n\n0^0=0
127821
"Dividing by nothing" doesn't mean you would do nothing.  It means, "how many piles of nothing (zero) would you have to add up to get to the original number?".  \n\nHow many piles of zero would you have to have in order to have 2?  The answer isn't even infinity, because you would still never have 2.  So it's not possible, and 2/0 can't be represented by any number.
523097
The ∞ mean infinity.  So, it goes from -infinity to 8, not including 8 itself.  And the other one goes from 5 to infinity, including 5.\n\nThe [ ] means that you include that end point, whereas ( ) means you don't include that point.
892605
(constant)/(2^n) when n->infinity => the limit is 0(zero)\n\nPS\nNot to be a a stickler for rules but is this really laptop related ? :))
95725
Zero of zero is undefined because of the definition of division and some basic field axioms.  It's not zero and it's not infinity, it's UNDEFINED.  I can prove it.\n\nThe multiplicative inverse of n is defined as the number 1/n such that n*(1/n)=1.  It's a property of zero that anything times zero is zero.  Therefore for any 1/n, 0*(1/n)=0, and since zero cannot equal one, zero has no multiplicative inverse.\n\nDivision by n is defined as multiplication by the multiplicative inverse of n.  Since zero has no multiplicative inverse, you cannot divide by zero.\n\nAll you people who said that anything divide by zero is infinity are just flat out wrong.  If n is not equal to zero, the limit as x approaches zero for the positive side of n/x is infinity, but that does not mean that n/0 is infinity.  Also, note that if you come at it from the negative side the limit is negative infinity.  n/0 is undefined because zero has no mutiplicative inverse so the expression 1/0 is mathematically meaningless  Also, the limit of 0/x as x approaches zero would be zero, not infinity.\n\nWhoever it was who did the calculator thing, calculators are a far cry from a mathemtical proof.   There are plenty of arithmetic problems that make perfect sense but can't be done on a calculator.  In fact, there are infinetly many of them.  And there are some properties of multiplication and addition that can be proven mathematically but are not true on a calculator.  But you and the first poster get major props for being the only people to answer this question and demonstrate anything resembing an basic understand of elementary arithmetic.\n\n______\nH2++ cannot exist because it would have to have a covalent bond but would have no electrons.  Two hydrogen nuclei can't form a diatomic molecule.  O-- is not going to exist in water because the hyrogen atom would have to dissociate from the water molecule one at a time, and OH- is more stable than O-- and H+.  It could in theory exist as 2H+ and O--, but OH- is a much happier molecule than O--.\n\nNothing can go faster than the speed of light because as an object approaches the speed of light it's mass becomes infinite, and so the force required to cause it to accelerator more becomes infinite.  You can't apply infinite force to something.  Normally I'd do out the math to show that, but it's 3:30 in the morning so I doubt I can make it coherent.\n\nTensor calculus is too complicated to explain at 3:30 in the morning.  You can read about it here: http://en.wikipedia.org/wiki/Tensor_calculus
971477
There is no real value for X. Here's a proof:\n\n0 = 1/(4-x)\n1 = 1/(4-x) + 1  (add 1 to both sides)\n1 = 1/(4-x) + (4-x)/(4-x)\n1 = (5-x)/(4-x)\n4-x = 5-x  (multiply both sides by 4-x)\n-x = 1-x\nx = x-1\n\nClearly not true. So the original equation was false.\n\n------------------------------\n\nBy the way, several others have mentioned that the limit as x approaches infinity (or -infinity) is 0, which is true. But you don't have limits mentioned...
1165584
Thats a common misconception. \n limit x tends to 0,    5/x is infinity\nbut tends to 0 is not that x is equal to 0.It means x is almost 0(you are moving towards 0) but not 0.\nU cannot divide bu 0,its a undefined proposition.
339198
2x0 = 0\nIt'll be the same as today... :P
306774
Anything divided by 0 is actually undefined, not infinity or 0. When you think about how that works, it makes sense:\n\nDividing a numerator by smaller numbers makes your number larger. Divide 4 by 2, you get 2. Divide 4 by 1, you get 4. Divide 4 by 0.5, you get 8. And so on until you are dividing by a number so small it's pretty close to 0. The overall number gets larger and goes off into infinity.\n\nBut, if you divide a negative number in the same manner, your number gets smaller. -4 by 2 is -2, -4 by 1 is -4, -4 by 0.5 is -8, etc. As you approach 0, your numbers go off into negative infinity.\n\nYou'll have the same weird effect if you divide by negative numbers - a positive divided by an increasingly smaller negative will yield negative infinity, and a negative divided by an increasingly smaller negative will yield positive infinity.\n\nYou can't have it both ways - dividing by zero yields both a positive and negative infinity! So someone a long time ago decided that since a number can't really have two values, it will be undefined.
28961
Still Zero since (0 / 2 = 0).\n\nWhen double below zero is used it is normally just to put emphasis on the fact that it is very cold.
532480
Undefined, again the common mistake is to treat infinity as a number.  Infinity does not play with the same rules as numbers.
923907
infinity isnt a set number.  nothing.
596523
If you are approaching zero from the left, then -1 divided by 0 is positive infinity.\nIf you are approaching zero from the right, then -1 divided by 0 is negative infinity.\n-1 divided by 0 is undefined because you get different results when coming in from the right side of 0 and the left side of 0.\nI learned this in Calc 1 (possibly Calc 2).\nThere are different levels (degrees) of infinity.
6900
-infinite < x < +infinite\n-1 < sin(x+2) < 1
580190
-4+4-4+4... infinity is not 0. It is Infinity the same goes for -4 + (4-4+4-4 .... infinity).\n\nInfinity is a consept instead of a real number.\n\nThe same as Infinity + 1 = Infinity.\n\nIt will go on for ever so there cant be a definitive answer.