Final answer:
The equation of the new function when shifting the quadratic parent function F(x)=x^2 down by 9 units is G(x)=x^2−9.
Step-by-step explanation:
If you shift the quadratic parent function F(x)=x^2 down 9 units, the equation of the new function would reflect a vertical translation downwards on the y-axis. A down shift by 9 units translates to subtracting 9 from the original function's value for each x. Therefore, the new function, G(x), would be G(x)=x^2−9. This is represented mathematically as taking the original function and subtracting 9 from it, resulting in a new function that graphically appears as the same parabola, just shifted down 9 units on the coordinate plane.