Definition:Ellipse/Minor Axis/Semi-Minor Axis

Definition

 * EllipseParts.png

Consider an ellipse $K$.

A semi-minor axis of $K$ is either half of the minor axis of $K$ from its midpoint to its endpoint.

In the above diagram, $O C_1$ and $O C_2$ are the semi-minor axes of $K$.

Also known as
Some sources do not hyphenate: semiminor axis.

Also see

 * Definition:Semi-Major Axis of Ellipse