$\"\"$

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The trigonometric esxpression is $\"\"$ .

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$\"\"$

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$\"\"$

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Remove the parentheses in the numerator.

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Using formula: $\"\"$ .

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$\"\"$

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$\"\"$

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Apply Pythagorean 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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$\"\"$ .