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.

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Latus Rectum of a ParabolaNext:
The Four Standard Forms of a Parabola