$\"\"$

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The function is $\"\"$ and $\"\"$ .

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Consider $\"\"$ .

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Differentiate with respective to $\"\"$ .

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$\"\"$

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$\"\"$ \ \

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$\"\"$ .

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$\"\"$

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Surface area:

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Let $\"\"$ is a continuous derivative on the interval $\"\"$ .

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The surface area is $\"\"$ , $\"\"$ is the distance between $\"\"$ and the axis of revolution.

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Where $\"\"$ is $\"\"$ and $\"\"$ . $\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ .

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The surface area of the bulb is $\"\"$ .

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$\"\"$

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The surface area of the bulb is $\"\"$ .