Graph the function where
The topographic map has level curves
The derivative dx/dy = 4y(c - y2) has zeros at y = 0 and y = ± √c.
The table shows that the curves are bell shaped.
The surface intersects the plane x = 0 in the parabola z = y2, and intersects the plane y = 0 in the curve
It intersects the plane z = 1 in the curve
x = (1 - y2)2.
The surface, shown in Figure 11.1.20, is shaped like a beaker spout.
Figure 11.1.20