I need to show f does not have a limit at c if c is not equal to 0. I've shown this true if c is rational, but I'm having a problem with if it's irrational, any help?
Suppose that then due to density .
Thus in any epsilon neighborhood of c there is a rational and an irrational number.
Thus on that neighborhood of a nonzero c the function is both c & 0.
Last edited by Plato; October 2nd 2008 at 03:59 PM.