00:01
Here we are asked to explain why the determinant of each of the given matrices equals zero.
00:07
So a matrix is going to have a determinant equal to zero if we have a row or a column of zeros.
00:16
So a zero row or column.
00:19
There's another situation in which that can happen, and that's if two rows or columns are the same.
00:26
So if we have two rows or columns with the same numbers, we would perform row operations, and one of those rows or columns would turn into zero.
00:39
So we'd end up with the first situation.
00:42
So two rows or columns are going to have exactly the same values, or we have a row or column of zeros.
00:49
Probably the easiest one to notice right here is matrix c, where we have a row of zeros.
00:56
So that explains why this determinant is equal to zero.
01:02
So let's look at the others here.
01:04
If i look across in matrix a, here we're looking, i look row by row first and then look at the columns.
01:13
But looking row by row, you can see that two rows are the same...