Definition:Major Axis of Ellipse/Definition 1

Definition

Consider an ellipse $K$ whose foci are $F_1$ and $F_2$.

The major axis of $K$ is the line segment passing through both $F_1$ and $F_2$ whose endpoints are where it intersects $K$.

In the above diagram, $V_1 V_2$ is the major axis of $K$.

Also see

• Equivalence of Definitions of Major Axis of Ellipse

• Results about the major axis of an ellipse can be found here.

Sources

• 1933: D.M.Y. Sommerville: Analytical Conics (3rd ed.) ... (previous) ... (next): Chapter $\text {IV}$. The Ellipse: $2$. To find the equation of the ellipse in its simplest form
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): major axis