The total sales of S (in thousands of DVD's) of a certain movie are given by the following formula where t is the number of months since the release of the DVD. Use the formula to answer the questions. 60t2 t2+100 30) = (E a) Find S'(t). 12000t (t2 +100)2 S'(t) = b) Find 3(5) and 9(5). The value of 3(5) rounded to the nearest hundredth is El. Use implicit differentiation to nd 31" and then evaluate y' at (- 2,0). 163yr = x4 + 3.!3 m Y'h 2,0} = D (Simplify your answer.)