5: Let the components of the Cauchy stress tensor for a body at time t be of the form [o]ij = 0 0 0 0 2 - 0 XXX2 -Bx3 where a and 3 are constants. For a certain point x, given by its coordinates (0, 3, a), find (a) three principal stress invariants of tensor . (b) Compute the principal stress components and associated principla directions of stresss. Verify that the principal directions of stress are mutually orthogonal. (c) Compute the maximum magnitude of shear stress and the plane on which it acts. (4 points)