and are the ends of the diameter of a circle. Show that the equation of the circle is:
If A and B are also points on the hyperbola and the circle on AB as diameter cuts the hyperbola again at C and D, prove that CD is a diameter of the hyperbola.
I can't prove the first part. I got:
, instead of the given equation. I found this from the midpoint of AB and half the length of AB.