$\"\"$

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The function is $\"\"$

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$\"\"$

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$\"\"$ (Integration involving inverse hyperbolic function)

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$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

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$\"\"$

\

\

$\"\"$

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Therefore the natural logarithm is $\"\"$ .