Derive the equation of the parabola with a focus at (6, 2) and a directrix of y = 1

Derive the equation of the parabola with a focus at (6, 2) and a directrix of y = 1.

a. f(x) = −1/2 times (x − 6)^2 + 3/2
b. f(x) = 1/2 times (x − 6)^2 + 3/2
c. f(x) = −1/2 times (x + 3/2)^2 + 6
d. f(x) = 1/2 times (x + 3/2)^2 + 6