If the equation of the plane passing through the line of intersection of the planes ax+by+cz+d=0,a1x+b1y+c1z+d1=0 and perpendicular to the XY-plane is px+qy+rz+s=0 then S=
dc1−d1c
dc1+d1c
dd1+cc1
aa1+bb1+cc1
The plane equation is (ax + by + cz + d) - cc1
(a1x+b1y+c1z+d1)=0