2. Let f be the function defined by f(x) = x³-3x² - 9x + 11. At which of the following values of x does f attain a local minimum? (A) 3 (B) 1 (C) -1 (D) 3

A company that makes and sells baseball caps has found that the total monthly cost C in dollars of producing x caps is given by the function C(x)=0.2x280x+9000. Find the production level that will minimize the monthly cost and find the minimum cost.