$\"\"$

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The equation is $\"\"$ .

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The volume of the solid generated revolving about the $\"\"$ - axis.

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The solid generated is cone.

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The cone extending from $\"\"$ to $\"\"$ .

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Formula for the volume of the solid with the Washer method $\"\"$ .

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The outer radius of revolution is $\"\"$ .

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The inner radius of revolution is $\"\"$ .

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Substitute $\"\"$ , $\"\"$ , $\"\"$ and $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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