Repeat Prob. 320 with x = 10, y = 40, z = 40, xy = 20, yz = 40, and zx = 20 MPa. Repeat

Repeat Prob. 3–20 with σx = 10, σy = 40, σz = 40, τxy = 20, τyz = −40, and τzx = −20 MPa.
Repeat Prob. 3–20, the state of stress at a point is σx = −6, σy = 18, σz = −12, τxy = 9, τyz = 6, and τzx = −15 kpsi. Determine the principal stresses, draw a complete Mohr’s three-circle diagram, labeling all points of interest, and report the maximum shear stress for this case.