Vertex = (2,2)
Directrix = y=2.5
line of symmetry is the Y value in the vertex = 2
subtract directrix from Y value of vertex
2 - 2.5 = -0.5
focus = 2, (2-.5) = (2,1.5)
now distance for a point
2.5 -y = sqrt(x-2)^2 +y-1.5)^2)
(2.5-y)^2 = (x-2)^2 + (y-1.5)^2
6.25 - 5y +y^2 = (x-2)^2 + y^2 -3y +2.25
(x-2)^2 = -2(y-2)