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i) 1 mark algebraic proof --> super easy
ii) recurrence formula for 3 marks using (i) identity... something like prove I(2n+1) = (2n/(2n+1)) x I(2n-1)
iii) prove I(2n+1) = (2^n * n!)/(1x3x5x...x(2n-1)) (2/3marks, can't remember)
iv) i couldn't even get close to typing this one...