http://www.mathhelpforum.com/math-he...1&d=1210999716
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The first part is a routine reduction formula question found all over MHF and indeed all over the net (you don't seem to have done much research). A MHF thread:
http://www.mathhelpforum.com/math-he...n-formula.html
For the other parts, I suggest you first play around with concrete values of n to get the feeling for the formula.