Please help to find the limit with hopital's rule

I can't even tell how many separate questions there are here (there are two "part b"s!), or what the instructions apply to.

Please make some attempt to follow the rules:
 
I am fuzzy on what is going on after n \ge 1, but I think this starts

It can be proved by complete induction that:

f(x)=xsin(x)    the nth derivative=xsin(x+nπ2)+nsin(x+(n1)π2).f(x) = x \cdot sin(x) \implies \text {the n}^{th} \text { derivative} = x \cdot sin \left (x + \dfrac{n \pi}{2} \right ) + n \cdot sin \left ( x + \dfrac{(n - 1) \pi}{2} \right ).
I am guessing that “complete induction” is what we call “weak mathematical induction.” I suspect this theorem is to be used (rather than proved) to find the indicated limits.
 
Top