Bad argument type, DET(M9)/M8(2,1) in App

[cyrille de brébisson]

Hello,

The problem here is that the result of the -DET(M9)/M8(2,1) is not a number, it's a fraction. And this symbolic object can not be stored in a purely numerical 'Home) matrix (M0).

Your program does mix CAS and Home, which, despite being ok in lots of cases, can sometimes lead to strange things.

My #1 advice would be to use CAS variables rather than home variables for your CAS programs.
If you do want to store the data in a home variables, add an evalf around the -DET(M9)/M8(2,1) code: M0(B,A):=evalf(-DET(M9)/M8(2,1));
and it should work.

cyrille