decreases most rapidly at x in the direction opposite
to the gradient vector, that is, in the direction of
.
Solution: From the proof of Theorem 15 we have:
where 
is the angle between
and u, and u is a unit vector.
The maximum value occurs when
,
.
The minimum value occurs when
,
.
Thus the function decreases most rapidly in the direction opposite to the gradient vector.
No Maple Code for this problem.
by: gm