Question

Let f = {(x, y) | x, y ∈ N and y = 2x} be a relation on N. Find the domain, co-domain and range. Is this relation a function?

Answer 1

X = {1, 2, 3, ….}

Y = {1, 2, 3, ….}

f = {(1, 2) (2, 4) (3, 6) (4, 8) ….}

Domain = {1, 2, 3, 4 ….}

Co-domain = {1, 2, 3, 4 ….}

Range = {2, 4, 6, 8}

Yes, this relation is a function.