Hey guys,im following a textbook example which involves matrices.

Basically variables N1, N2, N3 and N4 and their derivatives are given by the following..

(These arent matrices, just corresponding values)

I need to calculate a 2x2 matrix called the jacobian (J) which is given by..

where for my problem..

x1 = 0
x2 = 6
x3 = 20
x4 = 0
y1 = 5
y2 = 5
y3 = 12
y4 = 12

The textbook gives an answer for J as..

but I get..

i.e. two of the values are reversed.

Don't suppose anyone could clear up whether I'm right or wrong?I'm using MATLAB and still getting my answer.

Any help would be greatly appreciated.