5) (8pts) f(x) = -x3 - x2 + 5x - 9; (0, =) 5) Find Ay and f (x) Ax for the given function. 6) y = f(x) = x2 - x, x = 6, and Ax = 0.05 6) Use the differential to find a decimal approximation of the radical expression. Round to four decimal places. 7) (8pts) ~11 7) 8) (8pts) The total cost, in dollars, to produce x DVD players is C(x) = 130 + 6x - x2 + 5x3. 8) Find the marginal cost when x = 4. 9) (8pts) Find the dimensions that produce the maximum floor area for a one-story house that is rectangular in shape and has a perimeter of 162 ft. Round to the nearest hundredth, if necessary