Answer:
Yes
Explanation:
The inputs in a function should have only one output. In other words, each x value should only be assigned to one y value.
For example, (−2, −1),(1, 0),(1, 5),(2, 0) would not be a function because x value 1 is assigned to both number 0 and number 5.
In (1, 1)(2, 2)(3, 3)(4,4), non of the X values repeat themselves, so it IS a function.