Question

Write the equation when the focus is (2,-4) and the directrix is y=-6.

Answer 1

In vertex form for a parabola.

Answer 2

My first step: A drawing

Second step: Find vertex from that drawing.
Third step: Determine from that drawing if the parabola is faced up or down.
Faced up our p will positive
Faced down our p will be negative
Fourth step: After determining sign of p, determine p being the distance from the vertex to the focus.