Who can tell me the definition of ellipse? What is a fixed point? What is it?

An ellipse is the trajectory of a moving point P. The sum of the distances from the moving point P to the fixed points F 1 and F2 in a plane is equal to a constant (greater than |F 1F2|), and F1and F2 are called the two focuses of the ellipse. The mathematical expression is | pf1|+pf2 | = 2a (2a > | f1F2 |). [ 1]?

An ellipse is a conic curve, that is, the tangent of a cone to a plane. ? [2]?

The circumference of an ellipse is equal to the length of a specific sine curve in a period.

Chinese name

oblong

Foreign name

oval

Another name

oval

express

| pf 1 |+| PF2 | = 2a(2a & gt； |F 1F2|)

Applied discipline

mathematics

area of application

astronomy

area of application

Analytic geometry

Geometric category

Conical section