Hi
For the continuity of, we know that
and we want
. You may try to write
For the second question, I suggest you first show that. Then, you'll be able to show that
. As
is a dense subset of
and
is continuous, you'll be able to generalize the result to the real numbers.
Why don't you post text instead of images ? Images are annoying because one can't quote the question he is answering...