## Calculus 8th Edition

Traces are cross sections of the surfaces and planes parallel to the coordinate planes , that is, planes with equations $x=a, y=b$, or $z=c$ . To find a trace, we set one of the three variables $x,y,z$ to be a constant. For example, we set $x=0$ , then the trace is the cross product of the surface and the $yz$ plane (if the surface intersects with $yz$ plane).
Traces are cross sections of the surfaces and planes parallel to the coordinate planes , that is, planes with equations $x=a, y=b$, or $z=c$ . To find a trace, we set one of the three variables $x,y,z$ to be a constant. For example, we set $x=0$ , then the trace is the cross product of the surface and the $yz$ plane (if the surface intersects with $yz$ plane).