Principal and maximum shear stress. Given $\backslash$sigma $\_(\backslash$times $)=3$MPa,$\backslash$sigma $\_($yy$)=1$MPa, and $\backslash$sigma $\_($xy$)=2$MPa$\backslash$sigma $\_(1),\backslash$sigma $\_(2)\backslash$sigma $\_($mi$($n$)/($m$)$ax$)\backslash$alpha $\_($p$)$ and $\backslash$alpha $\_($s$)?$ Draw a $2-$D representation of the system at $\backslash$alpha $=0,\backslash$alpha $=\backslash$alpha $\_($p$)$ and $\backslash$alpha

$=\backslash$alpha $\_($s$)$ and include normal and shear stresses for each. $($Adapted from Humphrey & O'Rourke

$2\mathrm{.}10).$