HW4 Question for 4.3

[Yitong Zhou]

Hi,

for the answer given in terms of (x_{i+1}, x_i), should I give the answer in a recursive form or a sum form? I mean the answer should be like a_i=a_{i-1} or like a_n=\sum_{i=1}^{n-1}  a_i ?

Thanks,

Yitong