$\"\"$

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The equation is $\"\"$ .

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Consider $\"\"$ .

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Using integral theorem :

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

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

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The integral expression is $\"\"$ .

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In this case $\"\"$ .

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

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$\"\"$

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$\"\"$

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Apply summation formulae $\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$

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

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$\"\"$

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$\"\"$

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$\"\"$ .

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$\"\"$

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$\"\"$ .