(801, #35) The length *l*, width *w*, and height *h*,
of a box change with time. At a certain instant the dimensions are
*l* = 1m and *w* = *h* = 2m, and *l* and
*w* are increasing at a rate of 2m/s while *h* is decreasing at
a rate of 3m/s. At that instant find the rates at which the following
quantities are changing.

a)The volume

b)The surface area

c)The length of the diagonal
Solution: a) The volume:

b)The surface area:

c)The length of a diagonal
( By Pythagorean theorem we find )

No Maple Code for this problem.