$\"\"$

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The expression is $\"\"$ .

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Rewrite the expression.

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$\"\"$

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Using the half angle trigonometric 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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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ .

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$\"\"$

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$\"\"$ .