Hello, a.a!

The trunk of a tree is approximately cylindrical in shape

and has a diameter of 1 m when the height is 15 m.

If the radius is increasing at 3mm/year (0.003 m/year)

and the height is increasing at 0.4 m/year,

find the rate of increase of the volume of the trunk. . . . . when?

The volume of a cylinder is: .

At

After years: .

Then: .

Therefore: .