Part A)
The equation of the directrix is x=-5+8=3, x=3
Part B)
After using 'Perpendicular line' tool and 'Intersect' tool, we obtain the purple line and point A. A=(3,2)
The vertex V has to be on the axis of symmetry, halfway between points A and F. Vertex is V=(-1,2)
Part 3)
The focus is to the left of the vertex; therefore, the parabola opens to the left.
In general,
![\begin{gathered} Vertex:\left(h,k\right) \\ Focus:\left(h+p,k\right) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/t1qoxkb6xdgz0fuxsrvmwk9gygnne4dlmt.png)
Then, in our case,
![\begin{gathered} \Rightarrow\left(h,k\right)=\left(-1,2\right) \\ and \\ \left(h+p,k\right)=\left(-5,2\right) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/mnon0ugmzjk0ecfidf5xgq5kossifaayx0.png)
Thus, p=-4
Finding the equation in vertex form,
![\begin{gathered} x=(1)/(4*-4)\left(y-2\right)^2-1 \\ \Rightarrow x=-(1)/(16)\left(y-2\right)^2-1 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/flxvpgp13ew8f9glgskw0noljctyh4xgqi.png)
The answer is x=-(y-2)^2/16-1