A surface is modeled as z = x−y 2 + xy. At the x–y pair (x0, y0) = (5, 1), provide the vector equation for the line of steepest descent in terms of a “distance” parameter, s. This asks for a...

A surface is modeled as z = x−y
²
+ xy. At the x–y pair (x0, y0) = (5, 1), provide the vector equation for the line of steepest descent in terms of a “distance” parameter, s. This asks for a parametric relation in which x = f(s) and y = g(s).

In Figure 8.3, why does the water not flow from the plants on the bricks directly to the lowest point in the driveway, in the lower right? Sketch the elevation contour lines on the driveway.