If P(x1,y1) and Q(x2,y2) are conjugate points with respect to the circle x2+y2+2gx+2fy+c=0 Then x1x2+y1y2+g(x1+x2)+f(y1+y2)+c=0 The above state is true by definition The pole of line of circle x2+y2=9 at point (9,9) is, 9x+9y=9 x+y=1 Therefore, the second statement is false. Hence, option 4 is correct.