$\"\"$

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(a)

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The function is $\"\"$ over the interval $\"\"$ .

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

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$\"\"$

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$\"\"$

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(b)

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Graph :

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Graph the function and its derivative.

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$\"\"$

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$\"\"$

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(c)

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Observe the graph:

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Using graphing utility the critical points are $\"\"$ and $\"\"$ .

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$\"\"$

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(d)

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Consider the test intervals to find the interval of increasing and decreasing.

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Test intervals are $\"\"$ , $\"\"$ and $\"\"$ .

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Observe the graph :

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The function $\"\"$ is increasing on the intervals $\"\"$ and $\"\"$ .

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So $\"\"$ is positive on the intervals $\"\"$ and $\"\"$ .

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The function $\"\"$ is decreasing on the interval $\"\"$ .

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So $\"\"$ is negative on the interval $\"\"$ .

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$\"\"$

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(a)

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$\"\"$ .

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(b)

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$\"\"$

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(c)

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Critical points are $\"\"$ and $\"\"$ .

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(d)

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$\"\"$ is positive on the intervals $\"\"$ and $\"\"$ .

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$\"\"$ is negative on the interval $\"\"$ .