Mary Cordia Karl

Elizabeth Karl (Sister Mary Cordia) (November 16, 1893 – August 30, 1984[1]) was an American mathematician who contributed significantly to the theory of orthopoles in geometry.

She was Head of the Mathematics department at College Notre Dame of Maryland (now Notre Dame of Maryland University) until 1965,[2] when she retired with the title of Professor Emeritus.

Her PhD thesis was titled "Projective Theory of the Orthopoles".

A large summary of this work was published in the American Mathematical Monthly (June–July 1932, pages 327–338).

This correspondence can be illustrated by the following figure (where L is the line at infinity and A1, A2, A3 the base triangle): Such a projective apparatus makes it possible, given a point in the plane, to determine the lines that admit this point as orthopole.

The parabola associated to line A 2 A 3 is the degenerate line parabola { R 1 , P ′ 1 }