The line x + y + 2 =0 is a tangent to a parabola y2=4ax at the point A. If it intersect the directrix at B and tangent at vertex at C, then
The line x+y+2 = 0 is a tangent to a parabola y2=4ax at point A, it intersects the directrix at B and tangent at vertex at C, then (AC × BC) =