For question 2, how many marks for 2b) worth? I didn't get a=-3 and b=9 I got b as -4 because I didn't think to use what we learned in FP1 and just subbed in 1, 2, 3... n-2, n-1 and n and noticed that you had multiple (n-2) terms so did (n/2)(n-2) for some reason. Any idea how many marks I will have lost? I got a=-3 though...