Repeat Prob. 320 with x = 20, y = 0, z = 20, xy = 40, yz = 202, and zx = 0 kpsi. Repeat

Repeat Prob. 3–20 with σx = 20, σy = 0, σz = 20, τxy = 40, τyz = −20√2, and τzx = 0 kpsi.
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.