Area of Triangle Formed by the Two Foci and a Major-Axis Vertex

Area of Triangle Formed by the Two Foci and a Major-Axis Vertex

For a major-axis vertex:

$$A(a,0)$$

the triangle formed with the two foci has zero area because all three points are collinear.

$$\Delta=0$$

Usage

- Used to recognize degenerate configurations involving the foci and major-axis vertices.