$\"\"$

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

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Area of the function is $\"\"$ .

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Where $\"\"$ .

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Let number of subintervals be $\"\"$ .

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$\"\"$

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Substitute $\"\"$ in $\"\"$ .

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$\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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Apply summation formula $\"\"$ .

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Apply summation formula $\"\"$ .

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$\"\"$

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As $\"\"$ , then $\"\"$ .

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$\"\"$

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$\"\"$

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Area of the region is between $\"\"$ and $\"\"$ -axis is $\"\"$ sq-units.

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$\"\"$

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Graph the region:

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$\"\"$

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Area of the region is $\"\"$ sq-units.

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$\"\"$

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Area of the region is $\"\"$ sq-units.