
Doug C. answered 10/18/21
Math Tutor with Reputation to make difficult concepts understandable
Here is the graph referenced in the video:
desmos.com/calculator/weuhyfzvsz
For any point on a hyperbola, the difference between its distance to one foci with its distance to the other foci is a constant. The following graph illustrates that. You can also move the center to other than the origin by using sliders for the (h,k) variables..
desmos.com/calculator/g6bgf1xmea