Pair of Tangents, Chord of Contact and Chord with Midpoint of an Ellipse
Pair of Tangents, Chord of Contact and Chord with Midpoint of an Ellipse: Overview
This topic covers concepts, such as, Chord of Contact to an Ellipse, Length of Chord of Contact of an Ellipse, Pole and Polar with Respect to an Ellipse & Equation of the Polar of a Point with Respect to an Ellipse etc.
Important Questions on Pair of Tangents, Chord of Contact and Chord with Midpoint of an Ellipse
The line intersects the ellipse at two points. The tangents to the ellipse at these two points intersect at the point.

Let from a point chord of contacts of the tangents are drawn to the ellipse such that all these chords touch the ellipse , then the locus of the point is

The equation of the chord having as its mid-point with respect to the ellipse , is

If tangent to parabola intersect the ellipse at and and locus of point of intersection of tangents at and is a conic , then

From a point on the circle tangents and are drawn to the ellipse If the locus of the mid point of the chord describes the curve then

If line is intersecting ellipse at two distinct points and , then point of intersection of tangents at and :

The midpoint of a chord of the ellipse is . The equation of the chord is

is a diameter of . The eccentric angle of is . Then the eccentric angle of is -

If the point of intersection of the ellipses and be at the extremities of the conjugate diameters of the former, then -

Tangents are drawn from the points on the line to , then all the chords of contact pass through a fixed point, whose co-ordinates are -

The length of the diameter of the ellipse perpendicular to the asymptotes of the hyperbola passing through the first and third quadrant is

The chord of contact of the tangents drawn from to an ellipse touches the circle , then the locus of is

The chord of contact of the tangents drawn from to an ellipse touches the circle , then the locus of is:

Equation of chord of an ellipse , whose mid point is , is

If the chords of constant of tangents from two points and to the ellipse are at right angles, then is equal to

If a variable tangent of the circle intersects the ellipse at points and , then the locus of the point of intersection of tangent at and is

If and are the equations of a pair of conjugate diameters of an ellipse, then the eccentricity of the ellipse is

If the chords of contact of tangents from two points & to the ellipse are at right angles then is equal to

The area of the parallelogram formed by the tangents at the ends of conjugate diameters of an ellipse is
