00:01
In this question, we are asked to find the eigenvalues of the matrix a, and then also find the eigenvectors.
00:08
To find the eigenvalues, we need to solve the equation, determinant a minus lambda i equals 0.
00:18
And to get the matrix a minus lambda i, we simply need to subtract lambda from the entries on the main diagonal for the matrix a.
00:27
We are going to get 3 minus lambda, negative 2, 6, 0, or 0.
00:33
1 minus lambda 0 and 0 01 minus lambda.
00:43
Now we need to calculate the determinant of this matrix.
00:48
So determinant a minus lambda i equals to the determinant of this matrix and should be lambda 1 minus lambda and we need to put vertical bars since we are calculating the determinant.
01:31
And this matrix is a triangular matrix which means that its determinant determinant is simply the product of the entries on the main diagonal.
01:43
And this equals to 3 minus lambda, multiplied by 1 minus lambda squared.
01:53
And we want this to be equal to 0 to find the eigenvalues.
02:02
And it's easy to see that the roots are lambda equals to 3 and lambda equals to 1.
02:10
Now we need, so these are the eigenvalues.
02:15
There are two eigenvalues.
02:17
Now let's calculate the corresponding eigenvectors.
02:24
To find the eigenvectors, we need to solve, so let's call the eigenvalues lambda 1 and lambda 2.
02:31
To find the eigenvalues corresponding to lambda 1, we need to solve the equation a x, a minus lambda 1i times x equals 0, or it's equivalent to a minus 3i equals x equals 0.
02:54
To calculate a minus 3i, we need to subtract 3 from the entries on the main diagonal of the matrix a.
03:11
So we simply need to replace lambda by 3 here.
03:19
We are going to get 3 minus 3, 1 minus 3 and 1 minus 3.
03:26
So this is a minus 3i, and it simplifies to 0, negative 2, 6, 0 negative 2, 0, 0, 0 .000, 0.
03:38
And 0, 0, negative 2.
03:44
Now, the augmented matrix of the equation, a minus 3 i .x equals 0 ,000, is going to be 0 negative 2, 6, 0 ,0 negative 2, 0 ,000, and 0 ,0 negative 2.
04:10
And what we're going to do is we will subtract the second row from the first row, and multiply the third row by 3 and add it to the first row...