Some applications of trilinear coordinates
The author gives some interesting applications of trilinear coordinates in a (complex) projective plane. He considers conjugate pairs of points (with respect to a quadrangle) on given lines and conjugate pairs on lines through a given point. In particular in the complex Euclidean plane a formula is given for the coordinates of the unique pair of isogonal conjugate points on a given line. In case the given line is at infinity, the two conjugate points are Poncelet's ``circular'' points.
scientific article; zbMATH DE number 803751