5. Consider the circle x2 + y2 = 16 and the parabola y2 = 8x. They intersect at P and Q in the first the fourth quadrants, respectively. Tangents to the circle at P and Q intersect the x-axis at R and tangents to the parabola at P and Q intersect the x-axis at S.

Question

5.   Consider the circle x2 + y2 = 16 and the parabola y2 = 8x. They intersect at P and Q in the first the fourth quadrants, respectively. Tangents to the circle at P and Q intersect the x-axis at R and tangents to the parabola at P and Q intersect the x-axis at S.
  a). The ratio of the areas of the triangles PQS and PQR is?
  b).  The radius of the circumcircle of the triangle PRS is?
  c). The radius of the in-circle of the triangle PQR is?