00:01
We are given a matrix.
00:03
We are asked to show the matrix is non -defective and to find e to the a -t.
00:12
Our matrix a is negative 1, 3, negative 3, negative 1.
00:20
The characteristic polynomial a is negative 1 minus lambda squared, minus 3 times negative 3, or plus 9.
00:35
And so the characteristic equation of a is this equal to zero.
00:44
So we get negative 1 minus lambda is equal to plus or minus 3i, or that lambda is equal to negative 1 plus or minus 3i.
01:09
So we have the eigenvalues for a of lambda 1 equals negative 1 minus 3i, and so lambda 2 equals negative 1 plus 3i.
01:29
If v1 is an eigenvector associated with the eigenvalue lambda 1, then we have that a minus lambda 1, or plus 1 plus 3i, i times v1 is equal to the 0 vector.
01:53
Therefore, we have that negative 1 plus 1 plus 3i, or 3i, 3, negative 3, and negative 1, again, plus 1 plus 3i, which is 3i, times b11, b12, is equal to 0.
02:23
Of 0.
02:30
Therefore, we have the 3i v11 plus 3 v12 is equal to 0.
02:45
So v12 is equal to negative i.
02:54
Therefore, if v11 is equal 1, then v12 is going to be negative i.
03:00
So we get that our eigenvector v1 is 1 negative i.
03:10
If v2 is an eigenvector, if v2 is an eigenvector associated with eigenvalue lambda 2, and we have that a minus lambda 2 i, which is minus negative 1 plus 3i, i v2 is equal to the 0 vector.
03:40
Therefore, negative 1 minus negative 1 plus 3i, which is negative 3i, 3, i 3, negative 3, negative 3 i v2 1 b22 is equal to 0 0 therefore we get the negative 3 i v2 1 plus 3 v2 2 2 is equal to 0 so the v22 2 2 is equal to i v2 and therefore v2 1 is equal to 1 v2 2 2 is equal to i so we get that an eigenvector v2 is 1i.
04:47
Now since we have these eigenvalues, we know that a is non -defective, and therefore we can find two matrices s and d, such that a is equal to s -d inverse, where s is the matrix whose column vectors are the eigenvectors of a...