Derive the equation of the parabola with a focus at (2, -1) and a directrix of y = - =
2
f(x) = -(x + 2)2 - 3
4
7
3
f(x) = (x + 2)2 +
4
3
f(x) = -(x - 2)2 +
4
3
f(x) = -(x - 2)2 -
4