It is known that the equation of circle C is x2 + y2-6x-2y + 5 = 0. The moving line L passing through point P (2,0) intersects with circle C at two points P1 and P2. Let P1 and P2 be tangent lines L1 and L2 of circle C respectively. Let the intersection of L1 and L2 be m. prove that point m is on a fixed line, and work out the equation of this fixed line

It is known that the equation of circle C is x2 + y2-6x-2y + 5 = 0. The moving line L passing through point P (2,0) intersects with circle C at two points P1 and P2. Let P1 and P2 be tangent lines L1 and L2 of circle C respectively. Let the intersection of L1 and L2 be m. prove that point m is on a fixed line, and work out the equation of this fixed line

The center of C: (x-3) 2 + (Y-1) 2 = 5 is (3, 1) Let P1 (x1, Y1), P2 (X2, Y2), m (x0, Y0) Because p1m is tangent to circle C, MP1 ⊥ CP1 (4 points) so (x1-x0) (x1-3) + (y1-y0) (y1-1) = 0