Given the set a = {(x, y) | x + y = 1}, mapping f: a → B, under the action of F, the image of point (x, y) is (2x, 2Y), then the set B is______ .

Given the set a = {(x, y) | x + y = 1}, mapping f: a → B, under the action of F, the image of point (x, y) is (2x, 2Y), then the set B is______ .

According to the meaning of the question, if the mapping f: a → B is under the action of F, the image of point (x, y) is (2x, 2Y), and a = {(x, y) | x + y = 1}, then its image has 2x × 2Y = 2X + y = 2, and 2x > 0, 2Y > 0 holds; then the element (x, y) in B has xy = 1 holds; so the answer is {(x, y) | xy = 2, x > 0, Y > 0}