Originally Posted by

**pmh118** I have to find the minimum surface area of a right cylinder using numerical method

I have did it with differentation, I have looked back at some of my work and in all my books,

I can get that the surface area = 2pi(r^2) + 2V/r

And found that using arithmetic mean-geometric mean inequality

SA= 2pi(r^2) + 2V/r

SA= 2pi(r^2) + V/r + V/r

This the part I dont quite understand, how it changes to this

SA> 3 x cubedrt2pi{(r^2) (V/r)(V/r)}

I can just do it and be done but I realy prefer to understand what I am doing

any advise would be great thx