Final answer:
The equation for the cross section at z = 0 using x and y is x² - y² = 0, which represents a hyperbola with the x-axis and y-axis as asymptotes.
Step-by-step explanation:
The equation for the cross section at z = 0 using x and y can be represented as:
x² - y² = 0
This equation represents a hyperbola where the x-axis and y-axis are the asymptotes.