$\"\"$

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Find the derivative of $\"\"$ .

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Apply derivative on each side with respect to $\"\"$ .

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$\"\"$

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Chain rule of derivative: $\"\"$

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Derivative of inverse cosine function : $\"\"$ .

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$\"\"$

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$\"\"$ .

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$\"\"$

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$\"\"$

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The domain of the function $\"\"$ :

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Domain of cosine function is $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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The domain of the function $\"\"$ is $\"\"$ .

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Consider $\"\"$

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The domain of the function is $\"\"$

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$\"\"$

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The domain of the function $\"\"$ is $\"\"$ .

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$\"\"$

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The domain of the function $\"\"$ is $\"\"$ .

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The domain of the function $\"\"$ is $\"\"$ .