$\"\"$

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Prove that $\"\"$ .

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Definition of hyperbolic trigonometry : $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ .

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Since Hyperbloic identities : $\"\"$ .

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$\"\"$

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$\"\"$ .

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$\"\"$ .

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$\"\"$

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$\"\"$ .