Tutorial Exercise The radius of a right circular cone increasing at a rate of 1.9 in/s while its height is decreasing at a rate of 2.8 in/s. At what rate is the volume of the cone changing when the radius is 153 in. and the height is 113 in.? Step 1 The volume of a cone with base radius r and height h is given by V =rh. To find the rate of change of the volume, we need to find . By the Chain Rule, we know that dt av av dV dr dh dt dt Step 2 We are given that = 1.9 and dt = -2.8. dt av Also, =nrh and ar av ah 3 Step 3 When r= 153 and h = 113, then 11526x 11526 7803n 7803 Step 4 Substituting the above into the equation for the rate of change of the volume, we conclude that in/s. Submit Skip (you cannot come back)