Verify that each of the following stress systems obeys Cauchy's equations of equilibrium: (0) 1 = 22 = 12 (23 = (13 = 0, ty = pgx,, where p and g are constants, with b = -gej . (ii) (1 = (2 = (3 = 612 = 0, ty = wax, Ty = -Max,, where u and a are constants, with b = 0