The hyperbolic path formula is also the square /a of 2b.

The parabolic path formula is 2P.

The line segment connecting any two points on the ellipse is called the chord of the ellipse, the chord passing through the focal point is called the focus chord of the ellipse (so the long axis of the ellipse is also focus chord), and the focus chord perpendicular to the long axis is called the path of the ellipse (positive focus chord).

The line segment (or the length of the line segment) connecting any point on the ellipse with a focus is called the focal radius of the ellipse at that point, and any point on the ellipse has two focal radii.

Extended data

Geometric properties of ellipse

1, range: the focus is on the x axis -a≤x? ≤a，-b≤y≤b； The focus is on the y axis-b ≤ x? ≤b，-a≤y≤a .

2. Symmetry: symmetry about the X axis, symmetry about the Y axis, and symmetry about the origin center.

3. Vertex: (a, 0)(-a, 0)(0, b)(0, -b).

4. Centrifugal rate range: 0

5. The smaller the eccentricity, the closer to the circle, the greater the eccentricity and the flatter the ellipse.

6. Focus (when the center is the origin): (-c, 0), (c, 0) or (0, c), (0, -c).

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