1. How would I go about finding the gradient of the tangent?
2. How would I go about finding that the equation of the tangent at A is the line x=2y+12 ?
3. And how would I go about finding out that this line meets a second circle with
equation of x squared -24x +y squared +10y +149=0 in only one point?
This shows how to find gradient and equation of a tangent to a circle.