IMO 1969 LL BEL4

Let O be a point on a nondegenerate conic. A right angle with

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IMO 1969 LL BEL4

Origin: BEL

Problem

Let O be a point on a nondegenerate conic. A right angle with vertex O intersects the conic at points A and B. Prove that the line AB passes through a fixed point located on the normal to the conic through the point O.