Explanations, Ellipse
Trying to figure it out
Looks like an ellipse.
What are the foci? (seems obvious)
What is the tangent point, what is the major axis? (seems less obvious)
Explanation!
Use the scroll bar in the following applet to unfold the explanation.
Point A is a dynamic point, if you haven't done so before, in stage 6 can move it around.
In stage 7 you can also change the parameters.
also note - Point O in the original applet (which appears here at the bottom of the page) corresponds to point below and point F in the original applet corresponds to
The original applet
given a circle with center O and F an arbitrary point in it.
for every point A on the circle construct the perpendicular bisector to segment AF.
what happens when we move point A?