Given polar equation of circle is r2−8r(√3‌cos‌θ+sin‌θ)+15=0 or r2−8(√3r‌cos‌θ+rsin‌θ)+15=0 where r‌cos‌θ=x and y=rsin‌θ. It can be rewritten in cartesian form x2+y2−‌8(√3x+y)+15=0 ⇒‌‌x2+y2−‌8√3x−8y+15=0 ‌ Now, ‌‌‌‌ radius ‌‌=√(4√3)2+(4)2−15 ‌=√48+16−15=7
