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## #1 2006-06-08 09:48:55

Struggling
Member
Registered: 2006-06-08
Posts: 2

### Really Struggling!!!!

Hello guys.....i am really struggling with the following problem!!!! I have got exam in 2 days and the following question is from the preliminary exam sheet. Please help.

Heres the question:

A piston moves freely in a cylinder of radius r and height h. It is desireable for the surface of the cylinder above the piston to be kept to a minimum.

If the volume of this space is to be 500 c.c., find the values for the radius and height that give us the minimum surface area.

-Using the known volume write down a formula for h in terms of r. Write down a formula for the surface area in terms of r only.

- Using calculus, find the radius where a turning point occurs. Determine whether this radius produces a maximum or minimum surface area.

I am attaching a picture of this question!!!!

I seriously havent got a clue on what to do.

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## #2 2006-06-08 09:50:53

Struggling
Member
Registered: 2006-06-08
Posts: 2

### Re: Really Struggling!!!!

Heres the picture!!!!

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