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 = ??

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 = ??

amistre64 · Answer

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

amistre64 · Answer

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

amistre64 · Answer

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

amistre64 · Answer

2
    + -
    - +
3  + -
       ^^, gonna be a negative sooo

-2 is the cofactor if ive read this correctly :)

amistre64 · Answer

any of that sound familiar?

anonymous · Answer

yes i think so