Question

Compute the cofactors a'ij = (-1)^i+j det(Aij)?
Suppose A =
0 1 0 1
1 2 0 2
1 -2 1 2
0 -1 2 0

Needed a'32 = ??

Answer 1

i believe cofactors are the submatrix determinants associated with the ijth elements

Answer 2

row 3 col 2, cross them out

0 0 1
1 0 2

0 2 0

whats left is a 3x3 submatrix that needs a determinant produced

Answer 3

000
0 0 1 0 0
1 0 2 1 0 looks like the value will be a 2, but we need to account for the +- part of it
0 2 0 0 2
002

Answer 4

2
+ -
- +
3 + -
^^, gonna be a negative sooo

-2 is the cofactor if ive read this correctly :)

Answer 5

any of that sound familiar?

Answer 6

yes i think so