I have some trouble with Jacob built in function. when I calculate the partial derivative with respect to L1,L2,...L6, the answer should be 2L1,2L2....2L6. but the feedback from Mathcad shows all zeros matrix. as long as I know the answer should be diagonal matrix with 2L1,2L2,...2L6.
I am really appreciate if someone can give the advice. Thanks in advance.
P.S, enclose file, you can see the last equation, called Eqn(X,Y,Z,r.1,r.2....L.1,L.2...L.6)=~~