$\"\"$

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(a)

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

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Graph :

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Draw the coordinate plane.

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Graph the function $\"\"$ .

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$\"\"$

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$\"\"$

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(b)

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The function is $\"\"$ .

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Height of the cable at towers.

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Substitute $\"\"$ in the above equation.

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$\"\"$

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Height of the cable at towers is $\"\"$ .

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Height of the cable at the midpoint of towers.

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Midpoint of towers is $\"\"$ .

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Substitute $\"\"$ in the above equation.

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$\"\"$

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Height of the cable at the midpoint of towers is $\"\"$ .

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$\"\"$

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(c)

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The function is $\"\"$

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Apply derivative on each side.

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$\"\"$

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Slope at $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ .

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Slope of the function at $\"\"$ is $\"\"$ .

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$\"\"$

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(a)

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Graph of the function $\"\"$ :

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$\"\"$

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(b)

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Height of the cable at towers is $\"\"$ .

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Height of the cable at the midpoint of towers is $\"\"$ .

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(c)

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Slope of the function at $\"\"$ is $\"\"$ .