My textbook (regarding continuum mechanics) has the following identity that is supposed to be true for all tensors: a[itex]\cdot[/itex]Tb = b[itex]\cdot[/itex]TTa But I don't get the same result for both sides when I work it out. For each side, I'm doing the dot product last. For example, I compute Tb first and then computer the dot product of a[itex]\cdot[/itex]Tb. Is that right? I tried doing it the other way around also, but it didn't work out that way either. I'm still pretty new to this subject and teaching it to myself, so I figure I'm multiplying something incorrectly, but I don't understand what.