Hello to everyone. I'm trying to solve a mechanics of materials problem. It gives me the tension in the x-axis and the y-axis and also the tension on the plan x&y I have to determine the maximum and minimum shear stress. The problem is: When I solve the equation I get 131.23MPa and 48.8MPa but in the formula I have to choose the minimum shear stress and the minimum it would be the z-axis who is 0 since the problem didn't give me the value How can I set a condition for it to choose the minimum value: if the minimum shear were bigger than zero I would have 0 and if the minimum shear were less than zero I would have the minimum as the different from zero value. Thanks to everyone in advance.