Question

A water container is in the shape of a cylinder (of height h cm) with a hemispherical cap (of radius r cm)
on one end. The volume of the container is 1000 cm3

Neglecting the thickness of the material of the container, show that the total surface area of the container
is given by A=(5/3)πr²+((2000)/r)
Hence, find the dimensions h and r that will minimise the total amount of material needed to construct it.
Justify your conclusion and give your answers correct to 2 decimal places.

Answer 1

k let me give it a try

Answer 2

i thought the surface area of cylinder is \[2\pi r^2+2\pi rh\]

Answer 3

dude you short of πr²
A=2πr²+2πrh+πr²

Answer 4

http://math.about.com/od/formulas/ss/surfaceareavol_3.htm

Answer 5

a cylinder with a hemispherical cap on the other end

Answer 6

http://www.aaamath.com/exp79x10.htm

for surface area

Answer 7

oh ok..