we are given with the data of a parabola with vertex at (2, 2) and directrix at y = 2.5. the formua should be ax^2 + b x + c = y because of the directrix.
(x-h)^2 = 4a (y-k)
(x-2)^2 =4a (y-2)
a is the equidistant distance from focus to vertex and from vertex to directrix that is equal to -0.5