The radius r of a right circular cylinder is increasing at the rate of 5 cm/min and its height h, is decreasing at the rate of 4 cm/min. When r = 8 cm and h = 6 cm, find the rate of change of the volume of the cylinder.
Let the increasing rate of radius be
& and increasing rate of height be
Volume
DIfferentiating w.r.t 't':
VOlume is increasing at the rate of .