Q2 (7 points) Section 4.2: 66, 72. 10 66. [4 marks] For the expression (1+ )", determine the appropriate f(x) and a, and evaluate L(x) = f(a) + f'(a)(x - a). Calculate the numerical error in the linear approximation. 72. [3 marks] For y = 3x? - x + 6, find the differential and evaluate for x = 2 and dx = 0.1. Q3 (9 points) Section 4.3: 130, 140. 130. [6 marks) Find the local and absolute minima and maxima for the function y = x - 12x over the %3D interval (-0o, o0). 140. [3 marks] A company that produces cell phones has a cost function of C(x) = x2 - 1200x + 36, 400, where Cis the cost in dollars and x is the number of cell phones produced (in thousands). How many units of cell phones (in thousands) minimizes this cost function? Q5 (16 points) Section 4.5: 230. For the function f(x) = x' + x*, determine the following. Note that you must show all your work using derivatives. (A) [6 marks] Determine the intervals where f is increasing or decreasing. (B) [2 marks] Determine the local minima and maxima of f. (C) [6 marks] Determine the intervals where f is concave up and concave down. (D) [2 marks] Determine the inflection points of f.