(a) If a0, a1, a2, a3 is a list of four real numbers, what is 3i=1(a1 - a1-1)? (b) Given a list--a0, a1, a2,...,an--of n

(a) If a0, a1, a2, a3 is a list of four real numbers, what is ˆ‘3i=1(a1 - a1-1)?
(b) Given a list--a0, a1, a2,...,an--of n + 1 real numbers, where n is a positive integer, determine ˆ‘ni=1
(c) Determine the value of

100 (1-1) +2 i+I