Given:
A parabola has a vertex (1, -1) and direcrix (x = -5)
The general equation of the parabola will be as follows:
where the vertex = (h, k)
So, h = 1, k = -1
We will choose the positive sign because the directrix is on the left of the vertex.
the value of (a) is the distance between the vertex and the directrix
So, the equation of the parabola will be as follows: