The vertex of a parabola is the point (a,b) and latus rectum is of length /. If the axis of the parabola is along the positive direction of y-axis, then its equation is
(x−a)2=l2(2y−2b)
The equation of the parabola referred to its vertex as the origin is X2=IY where x = X+a, y = Y+b. Therefore the equation of the parabola referred to the point (a,b) as the vertex is (x−a)2=l(y−b) or (x−a)2=l2(2y−2b)