Duccius[?] - inscriptions, notably a tombstone of Lucius Duccius Rufinus at York[2] (http://museums.ncl.ac.uk/archive/arma/contents/iconog/tombston/cent1/uk/york/duccius.htm)
... trinomial of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must have y = b/(2a), so we add the square of b/(2a) to both sides, ...