Explanation

An ellipse is the set of points where the sum of distances from two fixed points (foci) is constant.

Standard equation (horizontal ellipse):
(x − h)² / a² + (y − k)² / b² = 1

Where:

• (h, k) = center

• a = distance along the major axis

• b = distance along the minor axis

Key points:

• If a > b → wider horizontally

• If b > a → taller vertically

Example:
(x² / 9) + (y² / 4) = 1 → center (0,0), a = 3, b = 2