The focus of a parabola is (4,7) and the directrix is y=8.

What is an equation of the parabola?

A: (x−4)^2=−(y−9)

B: (x−4)^2=−4(y−9)

C: (x−4)^2=−2(y−7.5)

D: (x−4)^2=−0.5(y−7.5)

p = - 1/2......so the equation is

4p(y-7.5) = (x - 4)^2

-2(y - 7.5) = (x - 4)^2 .........."C" is correct