$\"\"$

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The expression is $\"\"$ .

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Let $\"\"$ then $\"\"$ .

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$\"\"$ .

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The length of the opposite side is $\"\"$ .

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The length of the hypotenuse is $\"\"$ .

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$\"\"$ has the same range as $\"\"$ . \ \

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Trigonometric ratio : $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ .

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$\"\"$

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$\"\"$ .