Answer:
Step-by-step explanation:
Not sure what form you need this in, but it really doesn't matter, as you'll see in the final equation. I used the vertex form and solved for a:

We are given the vertex (h, k) as the origin (0, 0), and we have a point that the graph goes through as (4, -64). That's our x and y. Plugging in what we have:
gives us
-64 = 16a and
a = -4. That means that the quadratic equation is
which is both vertex form and standard form here, no difference.
For number 2 it's would be 12.8
Sorry I don't have time for number 3
Answer: D. 16.33
Step-by-step explanation:
Answer:
Fourth Quadrant
Step-by-step explanation:
a>0 = a is a positive number = +y
b<0 = b is a negative number = -x
[-b,-a] = [-(-x), -(+y)] = [x, -y]
[positive, negative] is on the fourth quadrant