MAT37x

Franklin College

Spring2004

Erich Prisner,

Draw the watershed lines, separating the areas where the lava aims towards the same sink, in the topographical map above.

Can you describe whether a point belongs to such a watershed
using only
partial derivatives
f_{x}
and f_{y} ?

Given the fnction and two points in the plane, how can you decide whether both belong to the same sink?