(i)
Given function F:S→T is defined as F={ ( a,3 ),( b,2 ),( c,1 ) }.
A function is said to be an inverse function if it is both one-one and onto.
As F( a )=3, F( b )=2 and F( c )=1. So, it is one-one and onto.
Thus, the function F −1 exists and it is given by F −1 :T→S as,
F −1 ={ ( 3,a ),( 2,b ),( 1,c ) }.
(ii)
Given, function F:S→T is defined as F={ ( a,2 ),( b,1 ),( c,1 ) } .
A function is said to be an inverse function if it is both one-one and onto.
As F( a )=2, butF( b )=F( c )=1. So, it is not one-one. Fis not invertible.
Therefore, the function F −1 doesn’t exists.