Math Is Fun Forum

Patjamet

Member

Registered: 2009-06-20

Posts: 5

Optimisation using derivatives - equation unknown

I'm having a bit of trouble with a maths problem which requires the use of derivatives to solve.

The question is:

"A cylinder of cheese is to be removed from a spherical piece of cheese radious 8cm. What is the maximum volume of the cylinder of cheese?"

I know that in order to solve this, the equation that needs to be maximised is the volume of the cylinder:

I know i've gotta differentiate that and find the maximum, but I'm having trouble using the additional information (sphere = 8cm r) to equate V to one variable and solve.

Help?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Optimisation using derivatives - equation unknown

Hi Patjamet;

This should help.
http://www.vias.org/calculus/03_continuous_functions_06_04.html

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Patjamet

Member

Registered: 2009-06-20

Posts: 5

Re: Optimisation using derivatives - equation unknown

Thanks man, thats perfect