Q2 (99 points) A. The function f = x² − 8x + y² − 12y + 48 has exactly one global minimum value on the - - constraint x + y = 8. Use the method of Lagrange multpliers to calculate that value. B. Using the method of Lagrange multipliers, find the maximum and minimum of the function f(x, y, z) = x + y + z subject to the two constraints x² + y² + z² = 9 and x² + y² — z² = 1.