Which of the following relations are functions? Give reasons. In case of a function, find its domain and range.
(i)
(ii)

Solution:

For a relation to be a function each element of first set should have different image in the second set(Range)
(i) f = {( – 1, 2), (1, 8), (2, 11), (3, 14)}
Here, each of the first set element has different image in second set.
is a function whose domain = { – 1, 1, 2, 3} and range

(ii) g = {(1, 1), (1, – 1), (4, 2), (9, 3),(16, 4)}
Here, some of the first set element has same image in second set.
is not a function.