TIP: – One – One Function: – A function is said to be a one – one functions or an injection if different elements of A have different images in B.

So, is One – One function

⇔ a≠b

⇒ f(a)≠f(b) for all

⇔ f(a) = f(b)

⇒ a = b for all

Now, f : A → B, denotes a mapping such that

f = {(2,2),(5,3),(6,4),(7,4)}

Here it is clear that every first component is from B and second component is from A

Hence this is mapping from B to A