Sales and advertising a store finds that its sales revenue changes at a rate given by
S'(t) = (-30)t2 + 360t dollars per day
where t is the number of days after an advertising campaign ends and 0 ≤ t ≤ 30.
(a) Find the total sales for the first week after the campaign ends (t = 0 to t = 7).
(b) Find the total sales for the second week after the campaign ends (t = 7 to t = 14).