9 A circle has centre at the point \(B ( 5,1 )\). The point \(A ( - 1 , - 2 )\) lies on the circle.
- Find the equation of the circle.
Point \(C\) is such that \(A C\) is a diameter of the circle. Point \(D\) has coordinates (5, 16). - Show that \(D C\) is a tangent to the circle.
The other tangent from \(D\) to the circle touches the circle at \(E\). - Find the coordinates of \(E\).