Let S be the graph of x2 +z2 +6z=16 in 3d-space.
(a) The intersection of S with the xz-plane is a circle with center____ and radius_____
(b) The intersection of S with the xy-plane is two lines, x=_____ andx=_____
(c) The intersection of S with the yz-plane is two lines, z =_____ and z =_____
