Not sure how to format a matrix properly on this forum. Someone feel free to let me know if you feel like it.
The matrix A =
1 3 1
2 1 1
-2 2 -1
I keep getting -10 for the cofactor for the entry in the 2nd row 1st column,
but it is actually 5.
The last row I cannot get correct at all. I get -4, 2, and 5 for the cofactors on the 3rd row. But the correct ones are 2, 1, -5.
I have no idea what I'm doing wrong, and it's weird as I feel like I have a pretty good understanding of the cofactors and I am able to calculate the rest of them.
Any feedback would be appreciated. I have a test this morning.