The circle S = x2 + y2 − 2x − 4y + 1 = 0 cuts the y-axis at A, B (OA: OB). If the radical axis of S ≡ 0 and S′ = x2 + y2 − 4x − 2y + 4 = 0 cuts the y-axis at C, then the ratio in which C divides AB is:
Let P be any point on the circle x2 + y2 = 25. Let L be the chord of contact of P with respect to the circle x^2 + y^2 = 9. The locus of the poles of the lines L with respect to the circle x2 + y2 = 36 is: