Question

OK, can anyone explain limits too me?
how can i tell if the limit exist or not?

Answer 1

let me give an example

limit as x tends to 0 IxI/x

Answer 2

substitute x..if the answer is undefined it does not exist

Answer 3

in your example..there's an answer BUT it is discontinuous at x = 0..thus the limit does not exist

assume this is the graph

the empty circle there is the point that the limit does not exist..BUT

the limit exists before and after the empty circle..got it?

Answer 4

http://www.calculus-help.com/tutorials
these guys do a great job of explaining limits