Answer:
(x, y) → (-x, y)
Explanation:
The coordinates of the points that make up the function are equal to (x, y).
If we reflect the function over the y-axis, the sign of the y-value stays the same due to still being on the same side of the x-axis. The x-value sign will be the opposite of its current value due to being reflected over the y-axis.
This leads us to the algebraic expression:
(x, y) → (-x, y)