The volume
of the water remaining in the tank after
minutes is
,
.
The rate at which water is draining from the tank
is
.
Consider
.
Differentiate on each side with respect to
.
.
Chain rule of derivatives:
.

(a)
\Rate at which water is draining from the tank after
min :

Rate at which water is draining from the tank after
min is
gallons/min.
(b)
\Rate at which water is draining from the tank after
min :

Rate at which water is draining from the tank after
min is
gallons/min.
(c)
\Rate at which water is draining from the tank after
min :

Her negative sign indicates that the level of the water in the tank was decreases.
\Rate at which water is draining from the tank after
min is
gallons/min.
(d)
\Rate at which water is draining from the tank after
min is

Rate at which water is draining from the tank after
min is
gallons/min.
(a) Rate at which water is draining from the tank after
min is
gallons/min.
(b) Rate at which water is draining from the tank after
min is
gallons/min.
(c) Rate at which water is draining from the tank after
min is
gallons/min.
(d) Rate at which water is draining from the tank after
min is
gallons/min.