I figure the best way to see if i'm understanding this is to try it on another example:

(this is the following question).Show that the function 0, \infty) \rightarrow \mathbb{R}" alt="f0, \infty) \rightarrow \mathbb{R}" /> given by is continuous using the usual definition.

In this case, is .

Starting from

where (which is acceptable since )

Let for any given .