8 A circle has equation \(( x - 2 ) ^ { 2 } + ( y + 3 ) ^ { 2 } = 25\).
- Write down
- the radius of the circle,
- the coordinates of the centre of the circle.
- Find, in exact form, the coordinates of the points of intersection of the circle with the \(y\)-axis.
- Show that the point \(( 1,2 )\) lies outside the circle.
- The point \(\mathrm { P } ( - 1,1 )\) lies on the circle. Find the equation of the tangent to the circle at P .