The method is to make point A a symmetrical point about the X axis and then tangent to the circle.

Set an equation by symmetrical point, and then the sum of the square of the distance from the point to the center and the square of the radius is the square of the tangent length.

As long as the tangent point is calculated according to the equation, there are two tangent points.

Finally, substitute it into the linear equation and you will know.

The most important thing is to do it yourself. Only if you have done it yourself will you be impressed.