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Use the distance formula to identify if a parabola can exist when provided a point, focus and directrix.
https://www.khanacademy.org/math/precalculus-tx/xecf67014514b60db:conics/xecf67014514b60db:general-conic-characteristics/v/identifying-if-a-parabola-exists-from-given-key-features

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