0:00
Hello.
00:01
So here we have, and we take a given matrix a, and we basically concatenate it with the two -by -two identity matrix.
00:09
So we take a matrix a, put this vertical line, and then put the two -by -two identity.
00:14
The identity is just a matrix which has ones down the main diagonal and zeros everywhere else.
00:19
Now we're going to perform just elementary row operations to put this in reduced row echelon form on the left, basically just making the left -hand side equal to the identity.
00:29
And then what we have on the right hand side will then become our inverse matrix.
00:35
So what we want here to, i mean, we want to first have a one in our leading spot.
00:42
Okay.
00:43
So to do so, what do we want to do? well, we want to take basically multiply, right, by negative one -fourth.
00:53
That's going to put a one in our leading spot.
00:57
So we're going to do, so row one is going to become negative one -fourth times row one or negative row one over four.
01:11
Okay...