$\"\"$

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The function is $\"\"$ .

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Consider $\"\"$ .

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Hyperbolic trigonometry : $\"\"$ .

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Rewrite the equation.

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$\"\"$

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

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$\"\"$

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If $\"\"$ then $\"\"$ .

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Therefore,

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$\"\"$

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Hence $\"\"$ .

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Therefore, $\"\"$ .

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$\"\"$

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$\"\"$ .