Show that the height of a closed right circular cylinder of given surface and maximum volume, is equal to the diameter of its base.

Explanation

Let r and h be the radius and height of the cylinder respectively


Then, the surface area of the cylinder is given by


`s=2pir^2+2pirh`


`h=(s-2pir^2)/(2pir)`=`s/(2pi)(1/r)-r`


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