The vertex of the parabola $x^2 + 8x + 12y + 4 = 0$ is

Find the coordinates of the focus,axis of the parabola,the equation of the directrix,and the length of the latus rectum for $x^{2} = -16y$.

If $a > 0$ and $b^2 - 4ac = 0$,then the curve $y = ax^2 + bx + c$

Let a focal chord $12x + 5y - 27 = 0$ of the parabola $y^2 = kx$ intersect the parabola at the points $P$ and $P^{\prime}$. If $S$ is the focus of this parabola,then $9(SP + SP^{\prime}) = $

The locus of the points of intersection of perpendicular normals to the parabola $y^2=4ax$ is

The length of the latus rectum of the parabola $y^2+8x-2y+17=0$ is