Question

Find the standard form of the equation of the parabola with a focus at (3, 0) and a directrix at x = -3.

Answer 1

Would you like to derive the equation? Or just do a little pluggin in? I prefer deriving.
set the distance from the point (x,y) on the parabola to the focus equal to the distance from the point (x,y) on the parabola to the point (-3,y) on the directrix.