The radius of the circle with the polar equation r2-8r(√3cosθ+sinθ)+ 15 = 0 is
8
7
6
5
The polar equation of the line perpendicular to the line sin θ- cos θ =1/r and passing through the point (2,π/6) is
sin θ + cos θ =(√3 +1 )/r
sin θ - cos θ =(√3 +1 )/r
sin θ + cos θ =(√3 -1 )/r
cos θ - sin θ =√3 /r