A small aircraft starts its descent 4 miles west of the runway from an altitude of
h = 3/2 miles (see figure).
(a)
Find the cubic function
f(x) = ax3 + bx2 + cx + d
on the interval [−4, 0] that describes a smooth glide path for the landing.
(b)
The function in part (a) models the glide path of the plane. When would the plane be descending at the greatest rate?