TST II 2009, Problema 3

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Laurian Filip
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TST II 2009, Problema 3

Post by Laurian Filip »

Demonstrati ca varfurile unui pentagon convex ABCDE sunt conciclice daca si numai daca
\( d(E,AB) \cdot d(E,CD)= d(E,AC) \cdot d(E,BD)= d(E,AD) \cdot d(E,BC), \) unde prin \( d(X,YZ) \) se noteaza distanta de la punctul X la dreapta YZ.
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mumble
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Post by mumble »

Vezi aici ceva solutii sintetice si o surprinzatoare solutie algebrica ce implica proprietati ale conicelor.
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