Question

Let A = {1,2, 3, 4} and B = {4, 8,9,10}.
A function f : A $\to$ B given by
f = {(1, 4), (2, 8), (3,9), (4,10)}. Identify the type of function.

• A. Many-one and Onto function
• B. Identity function
• C. One-to-one function
• D. One-to-one and Onto function

Answer 1

The correct option is D One-to-one and Onto function

One to One function: Distinct elements of A have distinct images in B.
Onto function: Every element in B has a pre-image in A.
Here both conditions are satisfied.
Hence it is a One-to-one and Onto function.