Consider the map from the uv-plane to the xy-plane defined by x=u+v, y=-v. Let S be the closed rectangular region (i.e. including both interior and boundary) of the uv-plane with corners at (0,0), (1,0), (0,2), (1,2) and suppose that R is the image in the xy-plane of S under the map given above. The region R is bounded by segments of four different curves (which may be straight lines) in the xy-plane. Give equations for these curves.