Dose exakt

Bestimmung des Minimums

`O(r) = 2 (pi r^2 + 1/r)`
`O'(r) = 2 (2 pi r - 1/r^2`
`O'(r) = 0 => 2 pi r = 1/r^2`
`2 pi r^3 = 1 => r^3 = 1/(2 pi) => r = root 3 (1/(2 pi))`

Höhe

`h = 1/(pi r^2) = 2 cdot r_(min)