Thread: help me(Matrices&Determinants)

need help on this particular question... with EXPL too . i have a exam tommorrow morning and this urgent. Thanks for the help guys...

Given the following determinant

| 6 2 |
| -1 5 |

Find the minor and cofactor of element a21.

Originally Posted by watsonmath

need help on this particular question... with EXPL too . i have a exam tommorrow morning and this urgent. Thanks for the help guys...

Given the following determinant

| 6 2 |
| -1 5 |

Find the minor and cofactor of element a21.

Okay,
a21 is located at,
The second row 1 coloumn.
The minor is canceling all rows and colomns along it, which is in this case.
|-1|=-1
The cofactor is,
(-1)^(2+1)*minor
Thus,
(-1)(-1)=1