heyy everyone

im really struggling to come to terms with optimsation, ive got to answer this question but i really have no idea how to do it

can u please have a look at it and see if u can show me how i go about doing it, thanks so much!

... A childs drinking beaker is in the shape of a cylinder with a hemisperical lid and a circular flat base. the radius of the cylinder is r cm and the height is h cm. the volume of the cylinder is 400cm cubed.

show that the surface area of plastic, A®, needed to make the beaker is given by A®= 3pi squared + 800/r .

( the curved surface area of a hemispere of radius is 2pi squared)

i also have to find the value of r which ensures that the surface area of plastic is minimised =S

thank you again xx