foci
An ellipse is the set of all points in a plane where the sum of the distances to two fixed points (foci) is constant. An ellipse is described by the equation: \[
\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1
\]
An ellipse is the set of all points in a plane where the sum of the distances to two fixed points (foci) is constant. An ellipse is described by the equation: \[
\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1
\]