Points: 0.5 of 1 Save K Find f'(x) and find the values(s) of x where f' (x) = 0. f ( x ) = ( 2x - 15) (x + 18) f' (x) = 6x -30x+36 x = (Type an integer or a simplified fraction. Use a comma to separate answers as needed.) 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. 4012 S(t) = - 12 + 150 a) Find S'(t) 12000t S' (1) = (12 + 150) b) Find S(10) and S'(10). The value of S(10) rounded to the nearest hundredth is Clear all Check answer an example Get more help