Question: A cone C, with height 1 and radius 1, has its base in the xz-plane and its vertex on the positive y-axis. Find a function g(x, y, z) such that C is part of the level surface g(x, y, z)=0. [Hint: The graph of f(x, y) = x2 + y2 is a cone which opens up and has vertex at the origin.]