Answer:
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