I have managed to do part (a) and used Abel's Identity to prove part (b), but I don't know how to proceed with part (c).
Any help would be great here.
Ok, from part b we're given .
Now let tend to infinity on both sides.
You need to show as . Then we know and we're done.
Notice since . So . This now becomes easier to verify as .
See here http://en.wikipedia.org/wiki/Logarit...otic_expansion.