Define derivative operator-matrix on the TI nspire cx cas

Question

I have a question regarding the TI nspire cx cas.

Im trying to define an operatormatrix like the matrices below, but - of course - the calculator only alows me to create a derivative with a given function (for example: d/dx(N1(x)) ).

I cannot create an "empty" derivative in the first matrix, which evaluates/derivates for example N1(xi,eta) in the second matrix when multiplied with each other.

Does anyone know how to define this kind of "operator-matrix" on the nspire cx cas?

Thanks in advance, Ramon

Answer 1

Found a way to get the work done by a workaround. It's not extremely comfortable, but worth the work, if you have bigger matrices.

Furthermore, I did not check, whether the summing up of the two matrices is allways a good idea or not, you better have a closer look at the results, when applying this technique:

It's not a perfect solution, but gets the work done when trying to do similar calculations...

Answer 2

All entries in a matrix must be an expression.

Unfortunately an operator such as d/dx is not an expression.

Therefore you can't make an operator matrix in NSpire.