Consider the variation of the Wyndor Glass Co. problem represented in Fig. 13.6, where the original objective function (see Sec. 3.1) has been replaced by Z = 126x1 – 9x12 + 182x2 – 13x22. Demonstrate that (x1, x2) = (8/3, 5) with Z = 857 is indeed optimal by showing that the ellipse 857 = 126x1 – 9x12 + 182x2 – 13x22 is tangent to the constraint boundary 3x1 + 2x2 = 18 at (8/3, 5).