$\"\"$

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The volume of the cone $\"\"$ .

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The rate of change of volume $\"\"$ .

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The diameter of the base of the cone $\"\"$ is approximately three times the altitude $\"\"$ of the cone $\"\"$ .

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Find the rate of change of height.

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Substitute $\"\"$ in the equation $\"\"$ .

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$\"\"$

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$\"\"$

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The volume of the cone is $\"\"$ .

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$\"\"$

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Apply derivative on each side with respect to $\"\"$ .

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$\"\"$

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Power rule of the deivative : $\"\"$ .

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$\"\"$

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Substitute $\"\"$ in the above equation.

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$\"\"$

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$\"\"$ .

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Substitute height $\"\"$ in the above equation.

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$\"\"$

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$\"\"$

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$\"\"$ ft/min.

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$\"\"$

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$\"\"$ ft/min.