0:00
Hello there.
00:01
So for this exercise, we got these two matrices, and we need to show that v corresponds to the inverse of this matrix a.
00:08
So just let's remember that if for a matrix a, there exists the inverse denoted in this way, then if a to the minus 1 is the inverse of a, then a times a to the minus 1 is equal to a minus 1 times.
00:32
A equals to the identity matrix.
00:35
So that means that we need to show that a times b is equals to b times a, which is equal to the identity matrix.
00:45
In this case, 2 by 2.
00:47
Okay, so we need to show that.
00:49
So let's proceed.
00:54
So let's start first with a times b.
01:01
So that means 1 minus 1 here, minus 1, 2 to 1 -1 -1 -1.
01:08
Rate.
01:09
Okay.
01:10
So just to remind you the multiplication of matrices is you take a row and multiply by the corresponding columns...