Thread: Please Help. A and Adj A with missing entries

The question is Asking to find A And Adj A when we have both with some missing entries.

A =
2 1 4
3 / /
1 / /

Adj A =
/ / -1
/ 8 /
/ 3 1

First Column is empty in Adj A.

The questions asks to find A and Adj a by finding the missing entries which i denoted here by using the symbol ( / )

Please help

Originally Posted by rodanader

The question is Asking to find A And Adj A when we have both with some missing entries.

A =
2 1 4
3 / /
1 / /

Adj A =
/ / -1
/ 8 /
/ 3 1

First Column is empty in Adj A.

The questions asks to find A and Adj a by finding the missing entries which i denoted here by using the symbol ( / )

Please help

For example look at the 2-2 entry in , which is 8: this entry is the determinant of the minor of the original matrix, i.e.: "erase" the second row and

the second column of A and calculate the determinant of the remaining 2x2 matrix: we get and we've found

the entry 3-3 of A.

Continue as above with other entries.

Tonio