00:01
In this problem, we are going to determine two matrices, the sum of which is non -zero, but the sum is not invertible.
00:09
Now we need to find 2 by 2 invertible matrices a and b.
00:14
And for this we can consider the 2 by 2 matrices to be a to be 1 ,203.
00:24
And we consider the matrix b to be the 2 by 2 mattress.
00:29
Is 4 3, 3, 0.
00:33
Now we want a and b to be invertible matrices.
00:37
So for that, let us calculate the determinants.
00:40
The determinant of a will be determinant of 1 -203, which will be 1 times 3 which is 3 minus 2 times 0 which is 0.
00:50
So this is equal to 3 and this is not equals to 0.
00:53
Since the determinant is not equals to 0, hence the matrix a is invertible.
00:58
We also need to find the determinant b.
01:01
So the determinant of b will be determinant 4 -3 -3 -0.
01:07
So this will be equals to 4 times 0 which is 0 minus 3 times 3 which is 9.
01:12
So this is equals to minus 9 and this is also non -zero...