$\"\"$

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The integral function is $\"\"$ .

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Assume $\"\"$ .

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Apply derivative on each side with respect to $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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Substitute $\"\"$ and $\"\"$ in the integral function.

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$\"\"$

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$\"\"$

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Trignometry identity $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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

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If $\"\"$ then by phythogarous theorem, $\"\"$ .

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

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$\"\"$

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$\"\"$

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$\"\"$ .

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$\"\"$

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$\"\"$ .