

If we intersect the tangent at parametric location t with the axes, we observe that each intersection is independent of one of the parameters of the e...



Take two tangents of an ellipse that are perpendicular to each other. The locus of all such points will be a circle.



Salmon calls this the “Eccentric angle”. For an ellipse, the point at parametric location t is the point



Take two nonparallel tangents of an ellipse, and the angle at their intersection can be calculated.



Expressed in terms of slopes we see that the product of the slopes of the diameter and its tangent is b^2/a^2.



Position the end of a diameter at parametric location t. Find the angle between the chords to a point at parametric location s.



We look at the locus of the intersections of the tangents at the end of the diameter and the focal chord through a point. This locus is a circle with ...



We examine lines through the foci perpendicular to the tangent at a point. Take the diagonals of the trapezoid formed by the tangent, the two perpendi...



