00:01
So let us start with the concept which we are going to use here for this question.
00:06
So if you have been given a matrix you have been asked to find the eigen values and eigenvectors you have to use the formula a minus lambda i its determinant to equate it to zero.
00:19
So we are given the matrix a is equals to 7 4 4 minus of 1 with the elements and obviously the identity matrix will be 1 0 0 1.
00:30
So let us find for the first we have to find the eigenvalues and eigenvector for this given matrix.
00:36
So let us apply a minus lambda of i so this can be equals to 7 4 4 minus of 1 negative of lambda of identity matrix 1 0 0 1.
00:48
So this will comes out equals to the 7 minus lambda 4 4 minus 1 minus lambda.
00:59
Now let us find this determinant of this 7 minus lambda 4 4 minus 1 minus lambda and this we have to equate it to 0.
01:08
Expand it along the first row will become 7 minus lambda times of minus 1 minus lambda negative of 4 into 4 will become 16 that will be goes to 0.
01:18
We can form this like an equation that is lambda square plus lambda minus of 7 lambda minus 7 minus 16 is equals to 0.
01:29
This implies that the lambda square minus 6 lambda minus 23 equals to 0.
01:35
This will gives us the lambda is equals to minus 6 plus minus under root over b square minus 4 c formula i am using that is 6 square minus minus will get 4 into 23 divided by 2 times of a is nothing but 1.
01:51
So you will get the required values of lambda is equals to 17 .31 and lambda 2.
01:57
Okay this is lambda 1 this is lambda 2 minus 5 .3.
02:01
So these are what the eigenvalues which we were asked to find out.
02:06
Now also we have to find the eigenvectors...