00:01
Hello and welcome to problem 2 .4 .12.
00:03
We were asked to find the rank of a, write the matrices matrix a as the product of u and a transpose vector v.
00:13
The first matrix a is written here.
00:17
It's 1 -003, row 0, 2 -06.
00:21
As we can see, the third row is a scaling multiple of the first one, so we can use row, reduce row.
00:30
We can put this into reduced row echelon form and see that this matrix has a rank of 1.
00:37
So rank equals 1.
00:42
We'll just do the same thing for the second matrix.
00:46
We see that the first row is a constant multiple of the second, so the rank for this one is also 1.
00:55
Now, we're asked to write this in a form of a u times a v, and we can do this by, pulling out the, pulling out just a random row and then multiplying the entire matrix by a vector of whatever column it is.
01:20
So if we look at this a, we see that the rows are going to be 1 -003 and 2 -06.
01:32
So those can be the v transpose.
01:36
We'll just write them here.
01:38
So just a 1 -0 -0 -3.
01:43
And we note that we're going to have a taller matrix in front...