$\"\"$

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(a)

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Differentiate the function $\"\"$

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Product rule of derivatives: $\"\"$ .

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$\"\"$

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$\"\"$ .

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(b)

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We have $\"\"$

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If $\"\"$ .

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$\"\"$

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(c)

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The function is $\"\"$

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Let $\"\"$

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$\"\"$

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Now find $\"\"$ .

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$\"\"$

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Substitute $\"\"$ value in $\"\"$ .

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$\"\"$

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(a) $\"\"$

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(b) $\"\"$

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(c) $\"\"$ .