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) =
8
4
12
16
am2=ln⇒a(1)2=1×2⇒a=2
A = (2, -4), B = (-2, 0), C = (0, -2) ⇒ AC . BC = 8