- The circle \(C\) has equation
$$x ^ { 2 } + y ^ { 2 } - 2 x + 14 y = 0$$
Find
- the coordinates of the centre of \(C\),
- the exact value of the radius of \(C\),
- the \(y\) coordinates of the points where the circle \(C\) crosses the \(y\)-axis.
- Find an equation of the tangent to \(C\) at the point ( 2,0 ), giving your answer in the form \(a x + b y + c = 0\), where \(a , b\) and \(c\) are integers.