$\"\"$

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The expression is $\"\"$ .

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Apply co-function identity: $\"\"$ .

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Let $\"\"$ .

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$\"\"$ .

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$\"\"$

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$\"\"$

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Since $\"\"$ .

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$\"\"$

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$\"\"$ .

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$\"\"$

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Consider $\"\"$ .

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Substitute the value $\"\"$ in above expression.

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$\"\"$ .

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Since $\"\"$ .

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$\"\"$ .

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$\"\"$

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The exact value of $\"\"$ is $\"\"$ .