Could someone please explain what these questions are asking for, and then how to do them?
Show that the following limits do not exist:
1. lim x --> 0 f(x) = { 0 when x < 0 , 1 when x > 0
2. lim x --> 0 f(x) = { x when x > 0 , x + 1 when x < 0
3. lim x --> 0 f(x) = { x^2 + a when x > 0 , 2...