Show that the distributions in Problems 8.2.1–8.2.5 are all diagonally symmetric. In the preceding problem, suppose that both f1 and f2 are elliptically symmetric but their corresponding functions...

Show that the distributions in Problems 8.2.1–8.2.5 are all diagonally symmetric.

In the preceding problem, suppose that both f1 and f2 are elliptically symmetric but their corresponding functions h(·) are not the same. Is f then elliptically symmetric or diagonally symmetric ?