SOLUTION: calculate the cofactor of the element 9 of this determinant: 1 2 3 4 6 7 8 9 -1 -2 -3 -4 -6 -7 -8 -9 Thank you and Merry Christmas

Algebra ->  Matrices-and-determiminant -> SOLUTION: calculate the cofactor of the element 9 of this determinant: 1 2 3 4 6 7 8 9 -1 -2 -3 -4 -6 -7 -8 -9 Thank you and Merry Christmas      Log On


   



Question 550088: calculate the cofactor of the element 9 of this determinant:
1 2 3 4
6 7 8 9
-1 -2 -3 -4
-6 -7 -8 -9
Thank you and Merry Christmas

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
1 2 3 4
6 7 8 9
-1 -2 -3 -4
-6 -7 -8 -9
---------------
calculate the cofactor of the element 9 of this determinant:
---------
If you mean where the 9 is, element 2,4:
---
= Det of
1 2 3
-1 -2 -3
-6 -7 -8
-----------
= 1(16-21) - 2(8-18) + 3(7-12) = -5 + 20 - 15
= zero