For a cylinder with a surface area of 20

20, what is the maximum volume that it can have? Round your answer to the nearest 4 decimal places.

2 answers

2πr^2 + 2πrh = 20
so, h = 10/πr - r

the volume is

v = πr^2h = πr^2(10/πr - r) = 10r-πr^3

so, find r when dv/dr=0
21