A parabola has focus (5,1) and directrix y=-3.
Where is the parabola’s vertex?

vertex = (5, - 1 )

Step-by-step explanation:

The focus and directrix are equidistant from the vertex

Since the equation of directrix is y = - 3 then the parabola is vertical,

The distance between the focus and directrix is

| 1 - (- 3) | = | 4 | = 2

Thus the vertex is 2 units below the focus

vertex = (5, 1 - 2 ) = (5, - 1 )

a is the right answer