Question

Let A = [p, q, r, s] and B = [1, 2, 3]. Which of the following relations from A to B is not a function?

पर्याय

• (a) R₁ = [(p, 1), (q, 2), (r, 1), (s, 2)]

• (b) R₂ = [(p, 1), (q, 1), (r, 1), (s, 1)]

• (c) R₃ = [(p, 1), (q, 2), (p, 2), (s, 3)

• (d) R₄ = [(p, 2), (q, 3), (r, 2), (s, 2)].

   

Answer 1

(c) R₃ = [(p, 1), (q, 2), (p, 2), (s, 3)

All the relations in (a), (b) and (d) have a unique image in B for all the elements in A.
R₃ is not a function from A to B because p ∈ A has two images, 1 and 2, in B.
Hence, option (c) is not a function.