Given h(x, y) = ln (4+ x² + y²)
a) Find the directional derivative at (-1,2) in the direction of (2,1)
b) Describe what part (a) tells us about the surface described by function h
c) At (-1,2), what is the direction of fastest increase?
d) Use Calcplot3D to form a contour plot for h.
e) Describe what this contour plot tells you visually about the surface in relation to different domain values.