Talk:Calculus/Surface area

went above my head
well if one does want to take averages then one should logically take sum (y+dy/2).ds and sum it up however if ds varies massively over the range (like a cone with a huge slope for the edge) then the calculations are still massively off

however if one views it as a small cylinders of thickness ds and radius y, like a step of cylinders..it somehow seems to make sense. perhaps someone can help correct my understanding