Describe the Vertical Traces X = 0 and the Horizontal $z = x ^ { 2 } + y ^ { 2 }$

Essay

Describe the vertical traces x = 0 and the horizontal traces z = -1 (if any) for the surfaces $z = x ^ { 2 } + y ^ { 2 }$ and $z ^ { 2 } = x ^ { 2 } + y ^ { 2 }$ .