The stress at a point in a machine component relative to an x, y, z coordinate system is...

The stress at a point in a machine component relative to an x, y, z coordinate system is given by

Referring to the parallelepiped shown in Fig. P1.70, calculate the normal stress σ and the shear stress at point Q for the surface parallel to the following planes: (a) CEBG, (b) ABEF, (c) AEG. [Hint: The position vectors of points G, E, A and any point on plane AEG are, respectively, , The equation of the plane is given by