$\"\"$

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The value of the trigonometric function $\"\"$ , and the interval is $\"\"$ .

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Double-angle formulas : $\"\"$ ,

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$\"\"$ (or) $\"\"$ ,

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$\"\"$ .

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Find the value of $\"\"$ by using Pythagorean identity.

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Pythagorean identity : $\"\"$ .

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$\"\"$

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The angle $\"\"$ is in $\"\"$ .

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Since the secant function is negative in third quadrant, take $\"\"$ .

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$\"\"$

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Reciprocal identity : $\"\"$ .

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$\"\"$

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Pythagorean identity : $\"\"$ .

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$\"\"$

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Since sine function is negative in third quadrant, $\"\"$ .

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$\"\"$

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$\"\"$

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The value of $\"\"$ .

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$\"\"$

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$\"\"$

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The value of $\"\"$ .

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$\"\"$

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Quotient identity : $\"\"$ .

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$\"\"$ .

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$\"\"$

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The value of $\"\"$ .

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$\"\"$

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