At a point O, a solid body is subjected to a plane stress: = 16.5ksi, = -5.8ksi, Txy = 8.7ksi. Vector OA defines the normal to the inclined surface. Point A has coordinates: a = 1.0in, b = 1.4in, c = 2.5in. Determine: (a) the direction cosines for vector OA, (b) the resultant stress S on the inclined plane, (c) the normal stress on and the shear stress on the inclined plane, (d) the stress invariants and the principal stresses, (e) the absolute maximum shear stress. A (a,b,c) x