A geometry problem by Aditya Phaniram
A circle which is concentric with ellipse x^2/a^2 + y^2/b^2 = 1 and passes through the foci F¬ and F’ of the ellipse. The two curves intersect at four points. Let P be any point of intersection. If the major axis of the ellipse is 15 and area of the triangle PFF’ is 26, and then find the value of〖4a〗^2-〖4b〗^2.