Question

Let f and g be two real functions given by

f = {(0, 1), (2, 0), (3, −4), (4, 2), (5, 1)} and g = {(1, 0), (2, 2), (3, −1), (4, 4), (5, 3)}

Find the domain of fg.

Answer 1

It is given that f and g are two real functions such that

f = {(0, 1), (2, 0), (3, −4), (4, 2), (5, 1)}

and g = {(1, 0), (2, 2), (3, −1), (4, 4), (5, 3)}

Now,

Domain of f = D_f = {0, 2, 3, 4, 5}

Domain of g = D_g = {1, 2, 3, 4, 5}

∴ Domain of fg = D_f ∩ D_g = {2, 3, 4, 5}