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Unread 13-03-2005, 21:02
sanddrag sanddrag is offline
On to my 16th year in FRC
FRC #0696 (Circuit Breakers)
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Re: Proving smallest surface area of cylinder is when h=2r

Quote:
Originally Posted by Joshua May
I think you've got it so far.

I believe the next step to go is to find the derivative of A=2(pi)(r^2) + 2V/r, set that to zero, solve it, and do a sign test to show that this is a minimum point.
I thought that's what I do, but I'm not sure how to solve it. Please help, final is tomorrow morning!

Here's what I get for the derivative:

A'=4(pi)(r) +[(2r-2v)/(r^2)]

Is this right? If so, how do I solve it.
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