Question

Derive the equation of the parabola with a focus at (2, 4) and a directrix of y = 8.
f(x) = −1/8 (x − 2)^2+ 6
f(x) = 1/8 (x − 2)^2+ 6
f(x) = −1/8 (x + 2)^2+ 8
f(x) = 1/8 (x + 2)^2 + 8