Create the equation used to graph this graph:

 or  

Step-by-step explanation:

we know that

The general equation of a horizontal parabola open to the left is equal to

where

(h,k) is the vertex of the parabola

p is the focal distance (distance from the vertex to the focus)

In this problem we have

The vertex is the point (2,-4)

so

The Focus is the point F(1,-4)

so

the focal distance p=2-1=1 ---> distance from the vertex to the focus

substitute in the formula

answer:

a=9

step-by-step explanation: lmk if you need a explanation