Sketch D and g(D) from the description of D and change of variables (x, y) = g(u, v). X 13) u = xy, v = where D is the rectangle 1 s x s 4, 7 sys 2 N 7- 6- 6+ 5+ 5+ 4- 3+ 3+ 2+ 2+ 1+ 3 4 5 6 7 u 2 3 4 5 6 7 X