00:01
Hello, welcome to this lesson.
00:03
In this lesson we would find the determinant of this matrix.
00:09
So we would expand it along the first the first row.
00:14
So we have plus minus and plus.
00:18
We can equally expand it along the last column so that we have zero there.
00:24
We have to do for one row to find the minor for one and minor for three and multiply them.
00:34
We can equally do and expand using the cofactor method along any row or any column.
00:41
So we had positive, negative and positive base on this.
00:48
So we have negative one to the power the row plus the column.
00:53
For example, we have the first row and the first column.
00:57
With that we have one plus one.
01:01
So negative one to the power one plus one which is two equals to a positive one.
01:08
So that is how we have these values.
01:13
So what we do is that we have six multiplying the minor of six.
01:20
And by the minor of six we would delete the first row and the first column so that we are left with negative one zero negative four and three.
01:45
And this is minus so there's minus already and there's minus one...