$\"\"$

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The Elevation of function is $\"\"$ .

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Find the rate of change of elevation at $\"\"$ .

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Apply limits on each side.

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Calculus concept is applied here.

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Rate of change in function is

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$\"\"$ .

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$\"\"$

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$\"\"$

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Take out the common term $\"\"$ .

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$\"\"$

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$\"\"$

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Substitute $\"\"$ .

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$\"\"$

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Substitute $\"\"$ .

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$\"\"$

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Rate of change of elevation at $\"\"$ is $\"\"$ .