Not returning correct Matrix Calculation

[Amer7]

(04-27-2021 10:56 PM)Albert Chan Wrote:  

(04-27-2021 08:20 PM)Amer7 Wrote:  I guess something is wrong in Excel ( all formulas seemed ok).

It is possible the problem is not Excel.
From your attached screenshot, there were a picture suggesting A51 = A62, A61 = -A52.

Your provided A (row 5 and row 6) does not match this symmetrical pattern.
Not terribly off, but enough to mess up the numbers.

I have found the Issue, Im not sure why this happens. When number in column F have in front of them - ( minus, aka they are negative) Inverse matrix is not going to be the same as in Excel.
So when I input O matrix as all positive numbers I get inverse matrix correct.
And in last matrix calculation ( excel uses formula example (trn(A)*N) + O and when I adjust this to (trn(A)*N) - O I get everything correct.

I'm not sure why this difference is happening between calculator and Excel.
-Downloaded a virtual TI Nspire to check, they also get the same Matrix as we on our HP Prime.
-So its something querk of Excel.