Let u1, u2, · · · , un be independent uniform random variables over [0, ? ] with the probability density function (p. d.f) f(x) = 1 ? , x ? [0, ? ], ? > 0. let u(1), u(2), · · · , u(n) be the order statistics. also let x = u(1)/u(n) and y = u(n) . (a) (5pts) find the joint probability density function of (x, y ). (b) (5pts) from part (a), show that x and y are independent variables