Determine the average cost function C(x) = C(x)/x. To find where the average cost is smallest, first calculate C'(x), the derivative of the average cost function. Then use a graphing calculator to find where the derivative is 0. Check your work by finding the minimum from the graph of the function C(x). C(x) = 1/2 x^3 + 4x^2 - 4x + 30 Determine the average cost function. C(x) =