$\"\"$

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The trigonometric expression is $\"\"$ .

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Consider $\"\"$ .

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Multiply the numerator and denominator by $\"\"$ .

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$\"\"$

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Apply formula : $\"\"$ .

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$\"\"$

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$\"\"$

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Pythagorean identity : $\"\"$ .

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$\"\"$

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$\"\"$ . $\"\"$

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The solution is $\"\"$ .