Answer:
g(x) = -x
Explanation:
The reflection of a function over the y-axis involves changing the sign of the x-values (i.e. making them negative) while keeping the y-values the same. This is because the y-axis is the vertical axis, and to reflect a point or function across a vertical line, you effectively swap the positive and negative horizontal coordinates.
So, for the given function f(x) = x, when it is reflected over the y-axis, it becomes:
g(x) = -x