A rectangular tank with a bottom and sided but but no top is to have volume 500 cubic feet. Determine the

dimensions (length, width, height) with the smallest possible surface area.

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- March 9th 2013, 01:06 PM #1

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- March 9th 2013, 03:13 PM #2
## Re: max/min

Hi apatite!

For a minimal surface area, the top of the tank will be square.

Let's say the side of this square is x.

And let h be the height of the tank.

Then the volume is and the surface area is .

Can you combine these equations to find A as a function of x?

Afterwards its derivative needs to be zero, which will give you x.

- March 12th 2013, 07:54 AM #3

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- March 12th 2013, 08:05 AM #4

- March 12th 2013, 08:17 AM #5

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- March 12th 2013, 08:19 AM #6

- March 12th 2013, 08:24 AM #7

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- March 12th 2013, 08:28 AM #8

- March 12th 2013, 08:46 AM #9

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- March 12th 2013, 09:00 AM #10