A company determines that monthly sales S(t), in thousands of dollars, after t months of marketing a product is given by S(t) = 2t* - 55t- + 280t + 170. a) Find S'(1), S'(3), and S'(5) b) Find S"(1), S"(3), and S'(5). c) Interpret the meaning of your answers to parts (a) and (b). (a) First, find S'(t). S'(t) = 0 S'(1) = (Simplify your answer.) S'(3) = 0 (Simplify your answer.) S'(5) =0 (Simplify your answer.) (b) First, find S"(t). S"(1) = 0 S"(1) = (Simplify your answer.) S''(3) = 0 (Simplify your answer.) S'(5) =0 (Simplify your answer.) (c) What do the answers from parts (a) and (b) say about the monthly sales? After 1 months of marketing, sales are and the after 3 months of marketing, sales are and the and after 5 months of marketing, sales are and the