Question

Let A = {1, 2, 3}, B = {4, 5, 6, 7} and let f = {(1, 4), (2, 5), (3, 6)} be a function from A to B . Show that f is one-one.

Answer 1

The given function f:A→B is defined by f( x )={ ( 1,4 ),( 2,5 ),( 3,6 ) }, where A={ 1,2,3 } and B={ 4,5,6,7 }.

Since f( 1 )=4, f( 2 )=5 and f( 3 )=6.

The images of distinct elements of A under f are distinct.

Hence, the given function f is one-one.