Find the standard form of the equation of the parabola with a focus at (3, 0) and a directrix at x = -3.
Ay = (1/12)x^2
B-12y = x^2
Cx = (1/12)y^2
Dy^2 = 6x
Ay = (1/12)x^2
B-12y = x^2
Cx = (1/12)y^2
Dy^2 = 6x