apogee vs vertex

apogee

noun
  • The highest point. 

  • The point, in any trajectory of an object in space, where it is farthest from the Earth. 

  • The point, in an orbit about the Earth, that is farthest from the Earth: the apoapsis of an Earth orbiter. 

  • The point, in an orbit about any planet, that is farthest from the planet: the apoapsis of any satellite. 

vertex

noun
  • The highest point, top or apex of something. 

  • One of the elements of a graph joined or not by edges to other vertices. 

  • A point in 3D space, usually given in terms of its Cartesian coordinates. 

  • The point where the surface of a lens crosses the optical axis. 

  • An interaction point. 

  • The point at which an axis meets a curve or surface. 

  • The common point of the two rays that form an angle. 

  • A sharp downward point opposite a crotch, as in the letters "V" and "W" but not "Y". 

  • The point where the prime vertical meets the ecliptic in the western hemisphere of a natal chart. 

  • A point on the curve with a local minimum or maximum of curvature. 

  • The highest surface on the skull; the crown of the head. 

How often have the words apogee and vertex occurred in a corpus of books? (source: Google Ngram Viewer )