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The integral is $\"\"$ .

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Theorem 4 of integration:

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If $\"\"$ is integrable on $\"\"$ , then $\"\"$ ,

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

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

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Width of the interval is $\"\"$ .

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$\"\"$ .

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

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$\"\"$

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The sum of $\"\"$ natural numbers is $\"\"$ .

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The sum of squares of $\"\"$ natural numbers is $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$ .