Problem 2 Let the Cauchy stress tensor T be given in terms of the canonical basis by U 1 1 [T]: 0 1 2 12 3 1. Find the principal values and principal directions of the stress tensor. 2. Find the rotation tensor R that changes from the canonical basis into the rotated one (set the rational eigenvalue as the rst element of the basis). 3. Using the CayleyHamilton Theorem, calculate the inverse matrix [T'l]