what is the vertex of the function

Answer:
(4, -25)
Step-by-step explanation:
In this case, the quadratic formula is in the form:
ax² + bx + c
Since they also give you the formula for the vertex, you just need to plug the values in.
The x coordinate in the vertex is 8/2(1), or 4.
You take the x = 4 and plug it into your quadratic equation.
f(4) = 16 - 32 -9
= -25
The vertex is (4, f(4)) or (4, -25)
I hope this helps!