Let f and g be two functions given by
f = {(2, 4), (5, 6), (8, -1), (10, -3)} and g = {(2, 5), (7, 1), (8, 4), (10, 13), (11, -5)}.
Find the domain of f + g.
D(f) = {2, 5, 8, 10}
D(g) = {2, 7, 8, 10, 11}
Therefore, D(f+g) = {2, 8, 10}