Answer:
So there are two answers.
Explanation:
One answer is vertical strech which streches it vertically and that equation would be f(x)= -4x^2+3 (this is also reflected across the x-axis)
The other answer is if you want a vertical compression and that equation would be f(x)= -1/4x^2+3 (also reflected across the x-axis)
I hope this helps!