$\"\"$

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The trigonometric equation is $\"italic$ .

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$\"\"$ , let $\"begin$ and place $\"begin$ in third quadrant.

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The point $\"\"$ is on a circle of radius $\"\"$ .

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$\"begin$ .

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$\"\"$

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$\"Syntax$

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$\"begin$ .

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Since $\"\"$ and $\"\"$ .

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Therefore, $\"\"$ lies in third quadrant.

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$\"\"$ is negative and $\"\"$ is negative.

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Then $\"\"$ and $\"\"$ .

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$\"\"$

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(a) Find $\"italic$ .

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Apply Double-angle formula: $\"\"$ .

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Substitute $\"\"$ and $\"\"$ .

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$\"\"$

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$\"equal$

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$\"equal$

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$\"italic$ $\"equal$ .

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The exact value of $\"italic$ $\"equal$ .

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$\"\"$

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(b) Find $\"italic$ :

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Apply Double-angle formula: $\"italic$ .

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Substitute $\"\"$ and $\"\"$ .

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$\"\"$

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$\"equal$

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$\"equal$

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$\"equal$

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$\"equal$

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The exact value of $\"italic$ $\"equal$ .

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$\"\"$

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(c) Find $\"italic$ :

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Apply Half-angle formula: $\"italic$ .

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Substitute $\"\"$ .

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$\"table$

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$\"table$

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$\"\"$

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The exact value of $\"italic$ $\"\"$ .

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$\"\"$

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(d) Find $\"italic$ :

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Apply half-angle formula: $\"italic$ .

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Substitute $\"\"$ .

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$\"table$

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$\"table$

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$\"table$

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The exact value of $\"italic$ $\"\"$ .

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$\"\"$

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(a) The exact value of $\"italic$ $\"equal$ .

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(b) The exact value of $\"italic$ $\"equal$ .

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(c) The exact value of $\"italic$ $\"\"$ .

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(d) The exact value of $\"italic$ $\"table$ .