The plane $lx+my+nz=0$ moves in such a way that its intersection with the planes $ax+by+cz+d=0$ and $a'x + b'y + c'z+d'=0$ are perpendicular. Show that the normal to the plane through the origin describes in general, a cone of the second degree and find its equation.
My analysis
Here the given plane $lx+my+nz=0$ passes through the origin, so considering a normal dropped from origin is an incorrect term
Where am I going wrong?
Soham