9 A circle with centre \(C\) has equation \(x ^ { 2 } + y ^ { 2 } - 2 x + 10 y - 19 = 0\).
Find the coordinates of \(C\) and the radius of the circle.
Verify that the point \(( 7 , - 2 )\) lies on the circumference of the circle.
Find the equation of the tangent to the circle at the point \(( 7 , - 2 )\), giving your answer in the form \(a x + b y + c = 0\), where \(a , b\) and \(c\) are integers.
10 Find the coordinates of the points on the curve \(y = \frac { 1 } { 3 } x ^ { 3 } + \frac { 9 } { x }\) at which the tangent is parallel to the line \(y = 8 x + 3\).