Reconsider the linearly constrained convex programming model given in Prob. 13.4-7.
(a) Use the separable programming technique presented in Sec. 13.8 to formulate an approximate linear programming model for this problem. Use x1 = 0, 1, 2, 3 and x2 = 0, 1, 2, 3 as the breakpoints of the piecewise linear functions.