Answer: True. f is a function.
Explanation:
We know that function is a relation from a set of inputs to a set of possible outputs where each input is associated to exactly one output.
It means a relation for which each value from the set the first coordinate of the ordered pairs is related with exactly one value from the set of second coordinate of the ordered pair.
For the given set f= {(2, 5), (3, 2) (4, 6), (5, 1), (7, 2)}, here each input is associated to exactly one output.
Therefore, it is a function.