For each of the stress states listed below, find all three principal normal and shear stresses. Draw a complete Mohr’s three-circle diagram and label all points of interest.
(a) σx = 10, σy = −4
(b) σx = 10, τx y = 4 ccw
(c) σx = −2, σy = −8, τx y = 4 cw
(d) σx = 10, σy = −30, τx y = 10 ccw