A reader sent in this question: “ Hi. I was wondering if you could help me figure out finding a complex root problem. If you could explain how it's done that would be great The simple, easy solution ...

§CQ.1 THE FIRST GREAT ADVANCE in algebra after the Middle Ages was the general solution of the cubic equation, immediately followed by a solution for the quartic. I tell the full story in the next ...

Principal stresses are defined as the maximum and minimum normal stresses in a plane. Principal stresses are perpendicular to each other and oriented such that shear stresses are zero. For 3D stress ...

Proceedings of the National Academy of Sciences of the United States of America, Vol. 5, No. 4 (Apr. 15, 1919), pp. 111-114 (4 pages) ...