17. Find the maximum and minimum values of the given objective function of a linear programming problem. The figure below illustrates the graph of the feasible points. Objective function: z = 6x + 7y (0, 6) (8, 6) (0,3) (8, 2) (3,0)\f9. Write the expression below as the cosine of an angle, knowing that the expression is the right side of the formula for cos (a - B) with particular value for a and B. cos(120 ) cos(45) + sin(120) sin(459) 10. Find the exact value of the expres sion below. COS -1 3T COS = at 4