$\"\"$

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The expression is $\"\"$ .

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To find the value of $\"\"$ .

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$\"\"$ (Apply Pythagorean identity)

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$\"\"$ (Substitute $\"\"$ )

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$\"\"$

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$\"\"$

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$\"\"$ (Take the square root of each side)

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$\"\"$

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$\"\"$ is in the second quadrant, cos $\"\"$ is negative, $\"\"$ . $\"\"$

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Now find the $\"\"$ .

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$\"\"$ (Apply double-angle formula)

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$\"\"$ (Substitute $\"\"$ and $\"\"$ )

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$\"\"$ $\"\"$

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$\"\"$ (Apply double-angle formula)

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$\"\"$ (Substitute $\"\"$ )

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$\"\"$

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$\"\"$

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$\"\"$ $\"\"$

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$\"\"$ (Apply half-angle formula)

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$\"\"$ (Substitute $\"\"$ )

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$\"\"$

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$\"\"$

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$\"\"$ $\"\"$

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$\"\"$ (Apply half-angle formula)

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$\"\"$ (Substitute $\"\"$ )

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ $\"\"$

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The values of $\"\"$ , $\"\"$ , $\"\"$ and $\"\"$ .