. Let be xxy = P(X,Y), xyz = P(Y,Z), x = P(X, Z), dxY = f-1(xxv), drz = f-1(xyz), = Idxy —dyzi and Is = dxy -I-dyz. For dxy and dy2 fixed, let g : [0, ni H [I, u] be a function that takes as input the angle Q of the two lines from the center of Y to X and Y to Z (as depicted in Figure 35.4) and returns