$\"\"$

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Consider two vectors $\"\"$ and $\"\"$ .

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Find the dot product $\"\"$ .

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$\"\"$ .

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The vectors $\"\"$ and $\"\"$ are unit vectors.

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Therefore, $\"\"$ and $\"\"$ .

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If $\"\"$ is the angle between $\"\"$ and $\"\"$ , then $\"\"$ , since $\"\"$ and $\"\"$ .

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$\"\"$ or $\"\"$ .

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Since cosine function is even, $\"\"$ .

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$\"\"$ .

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$\"\"$

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$\"\"$ .