get a trial subscription to New Scientist (http://www.newscientist.com/) and look for p. 23 in the 9/6/99 issue in the archives (http://archive.newscientist.com/). A Jack T. Chick tract on evolution (http://www.chick.com/reading/tracts/0055/0055_01.asp) says Haeckel's "gills" grow into bones in the ear and glands in the throat and cites that as a source. Then edit ontogeny recapitulates phylogeny.
... of "=", that will make it a perfect square 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 ...