$\"\"$

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The mean distance of earth from the sun is $\"\"$ .

\

The length of the major is axis is $\"\"$ .

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The aphelion of earth is $\"\"$ .

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The aphelion of earth is $\"\"$ .

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The distance form the center of the ellipse to the sun (focus) is $\"\"$ .

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The equation of the orbit is $\"\"$ , where $\"\"$ .

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Substitute $\"\"$ and $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$

\

$\"\"$ . \ \

\

Substitute $\"\"$ and $\"\"$ in $\"\"$ .

\

$\"\"$ .

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The equation for the orbit is $\"\"$ . \ \

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$\"\"$ \ \

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The equation for the orbit is $\"\"$ .