A company determines that monthly sales S(1), in thousands of dollars, after t months of marketing a product is given by S(t) = 21- 501 + 2501 + 170. a) Find S'(2). S (3), and S (5) b) Find S"(2), S'(3), and S (5) c) Interpret the meaning of your answers to parts (a) and (b). (a) First, find S'(t). S' (t) =