MathDB
Math Prize 2015 Problem 11

Source:

September 22, 2015

Problem Statement

Let A=(2,0)A = (2, 0), B=(0,2)B = (0, 2), C=(2,0)C = (-2, 0), and D=(0,2)D = (0, -2). Compute the greatest possible value of the product PAPBPCPDPA \cdot PB \cdot PC \cdot PD, where PP is a point on the circle x2+y2=9x^2 + y^2 = 9.