The state of stress at a point is x = 6, y = 18, z = 12,

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.