Question

find the envelope of the system of concentric and coaxial ellipse of constant ​

Answer 1

Thus, in general, the envelope is a part of the discriminant curve. To find the equation of the envelope uniquely, the sufficient conditions are used. They assume that the following inequalities are satisfied

mark me

In mathematics, an ellipse is a curve in a plane surrounding two focal points such that the sum of the distances to the two focal points is constant for every point on the curve. ... The cross section of a cylinder is an ellipse, unless the section is parallel to the axis of the cylinder.