Answer:


Step-by-step explanation:
Given
Represent volume with v, height with h and radius with r

Required
Determine the values of h and r that uses the least amount of material
Volume is calculated as:

Substitute 432π for V

Divide through by π

Make h the subject:

Surface Area (A) of a cylinder is calculated as thus:

Substitute
for h in 


Factorize:

To minimize, we have to differentiate both sides and set 

Set 

Divide through by 


Cross Multiply


Divide through by 2

Take cube roots of both sides
![r = \sqrt[3]{216}](https://tex.z-dn.net/?f=r%20%3D%20%5Csqrt%5B3%5D%7B216%7D)

Recall that:




Hence, the dimension that requires the least amount of material is when

