Sосн=pi*r^2,
Sб=2pi*rh,
V=100л=100дм^3,
V=pi*r^2h, h=V/pi*r^2, Sб=2pi*rV/pi*r^2=2V/r
S=Sосн+Sб,
S(r)=pi*r^2+200/r,
S'(r)=2pi*r-200/r^2,
S'=0, 2pi*r-200/r^2=0,
(pi*r^3-100)/r^2=0,
pi*r^3-100=0,
r^3=100/pi,
r=∛(100/π) дм
Sосн=pi*r^2,
Sб=2pi*rh,
V=100л=100дм^3,
V=pi*r^2h, h=V/pi*r^2, Sб=2pi*rV/pi*r^2=2V/r
S=Sосн+Sб,
S(r)=pi*r^2+200/r,
S'(r)=2pi*r-200/r^2,
S'=0, 2pi*r-200/r^2=0,
(pi*r^3-100)/r^2=0,
pi*r^3-100=0,
r^3=100/pi,
r=∛(100/π) дм