I came across this problem and need some guidance if anyone can help me...

Let be such that exists. Suppose for some .

1) Prove for some contained in .

2) If find a formula for .

For part 1 I think it would be pretty easy to show that and so I'm thinking once we know that we can use that. Also, I believe that which I'm guessing is going to be important to know.

Part 2, I'm pretty lost on even where to start. I would appreciate a push start.