Ordinate And Double Ordinate of a Parabola

Ordinates of the parabola `y^2 = x`
Ordinate of a parabola is a line perpendicular to the axis of a parabola, starting from the axis and ending on a point on the parabola itself. Ordinates are always inside the parabola. The figure above shows a bunch of ordinates for the parabola `y^2 = x`.
Double ordinates for the parabola `y^2 = x`
A double ordinate, on the other hand, is the double of an ordinate. That is, it is a line perpendicular to the axis of the parabola and meeting the parabola at two points instead of just one. The figure above shows the double ordinates for the parabola `y^2 = x`.

Note: The double ordinate of a parabola passing through its focus are called its latus rectum.


  1. I'm writing a series of blog posts on the intersection of rote knowledge and higher order math reasoning. Would you be interested in seeing them and linking? Here's one that arose from a colloquy with Alfie Kohn, one of the clearest thinkers in education: http://www.ronaldfischman.com/#!Apples-andBasketballs/c1z4c/6C1264F1-A2FD-4B53-A06C-3D37E9EDE951

  2. Really helped! Thankz