A26.4 (i) (4 marks) When u = xy and v= y/x, compute the Jacobian determinants ə(u, v) Ə(x, y) (x, y > 0). Ə(x, y)' ə(u, v) (ii) (6 marks) Find the area of the region R in the positive quadrant that is bounded by the curves xy = a, xy = b; y = (1/2)x, y = 2x, where 0 < a < b are constants.