The radius of a right circular cone is increasing at a rate of 2 inches per second and its height is decreasing at a rate of 4 inches per second. At what rate is the volume of the cone changing when the radius is 10 inches and the height is 20 inches

The volume of cone changing at rate

Step-by-step explanation:

Let r be the radius of cone and h be the height of cone

We have to find the rate at which the volume of cone changing when r=10 in and h=20 in

Volume of cone

Differentiate w.r.t t

Substitute the values

Hence, the volume of cone changing at rate

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads

2.2°  

step-by-step explanation:

let θ = the angle of elevation.

tanθ =77/2020

tanθ = 0.038 12

      θ = tan⁻¹0.038 12

      θ = 2.2°