Answer
As given below
Work Step by Step
a) The domain is: $\{4.2,5,7\}$
The range is: $\{ 0,1.5,2.2,4.8\}$
The domain value 4.2 is mapped to two range values. The relation is not a function.
b) The domain is: $\{-2,-1,4,7\}$
The range is: $\{-4,-7,1,2\}$
Each domain value is mapped to only one range value. The relation is a function.
