$\"\"$

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(a)

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$\"\"$ .

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Differentiate on each side.

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$\"\"$ .

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Consider Right hand side of the expression.

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$\"\"$

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= Lefthand side expression of (1).

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$\"\"$ .

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$\"\"$

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(b)

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(i)

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The region is bounded by $\"\"$ , $\"\"$ , $\"\"$ and $\"\"$ .

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Rotation is about $\"\"$ -axis.

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

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$\"\"$ .

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$\"\"$

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$\"\"$ .

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$\"\"$ cubic units.

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(ii)

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The region is bounded by $\"\"$ , $\"\"$ and $\"\"$ .

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Rotation is about $\"\"$ -axis.

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

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Here $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ cubic units.

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$\"\"$

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(a) $\"\"$ .

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(b)

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(i) $\"\"$ cubic units.

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(ii) $\"\"$ cubic units.