Arie Bialostocki and Dora Bialostocki,
The incenter and an excenter as solutions to an extremal problem,
Forum Geometricorum, 11 (2011) 9--12.

Abstract.   Given a triangle ABC with a point X on the bisector of angle A, we show that the extremal values of BX/CX occur at the incenter and the excenter on the opposite side of A.

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