Definition:Ellipse/Minor Axis/Semi-Minor Axis

Definition

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

• Results about the semi-minor axis of an ellipse can be found here.

Linguistic Note

The plural of axis is axes, which is pronounced ax-eez not ax-iz.

Compare basis.

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): ellipse
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): ellipse

• Weisstein, Eric W. "Ellipse." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Ellipse.html