Dear Siahan

You can use Matlab functions inorder to find inversion and determinant of these matrices.

Firstly you should enter the entries of your matrix.

For example let A is a matrix:

A=[10 12 13;4 5 6;7 8 9]

After that you write this instruction: B=inv(A)

then you have the following:

A =

10 12 13 4 5 6 7 8 9

B =

   -1.0000   -1.3333 2.3333 2.0000   -0.3333   -2.6667    -1.0000 1.3333 0.6667

where B is the inversion of A.

the instruction for determinant is det(A).

if we write

A=[1 2 3;4 5 6;7 8 9] D=det(A)

then we have

A =

1 2 3 4 5 6 7 8 9

D =

  6.6613e-016

Regards

Thanks for the answer