$\"\"$

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The vector is $\"\"$ .

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The standard form of the vector is $\"\"$ .

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Compare $\"\"$ with $\"\"$ .

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

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Direction angle is $\"\"$ .

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Substitute $\"\"$ and $\"\"$ in formula.

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$\"\"$

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$\"\"$ .

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The point $\"\"$ lies in the fourth quadrant.

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Thus, the direction angle is

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$\"\"$

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Direction angle is $\"\"$ .

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$\"\"$

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Direction angle is $\"\"$ .