Polar Point

F lies on the line DE. FG and FH are tangents to the ellipse. As F runs along DE, all the chords pass through a common point.
This is the polar point of the line.

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Try dragging D and E.
What happens when the line touches the ellipse?
What happens when the line intersects the ellipse?
Can you position the line so the chords pass through the focus? What line is this?

App generated by Geometry Expressions