$\"\"$

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The function is $\"\"$ .

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Apply derivative with respect to x .

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$\"\"$

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Apply the difference rule of derivatives .

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$\"\"$

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Apply the power rule: $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ $\"\"$

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To find the critical numbers of $\"\"$ , equate $\"\"$ to zero.

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$\"\"$

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Take out common term $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ .

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Therefore the critical numbers are $\"\"$ and $\"\"$ . $\"\"$

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Critical numbers : $\"\"$ and $\"\"$ .

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