Answer:
g(x) = (x/2)^2
Explanation:
if we look at the Y values for each point they remain the same, however the X values change, which tells us that the X variable is being 'tampered' with.
to find the scale factor, we divide 4/2, and we get 2.
so g(x) = (x/2)^2
remember that when applying a scale factor to the X value the effect will be inversed, so we multiply the X value with 1/2. you can use desmos to double check.