$\"\"$

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The function is $\"\"$ , $\"\"$ .

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(a)

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Graph :

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Graph the function $\"\"$ .

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$\"\"$

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The graph visual approximate the critical numbers is $\"\"$ .

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(b)

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$\"\"$ .

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differentiate on each side with respect to $\"\"$ .

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$\"\"$ .

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Quetionent rule: $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ .

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Assume $\"\"$

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$\"\"$ .

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differentiate on each side with respect to $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ , $\"\"$ .

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Quetionent rule: $\"\"$ .

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Case (i):

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$