00:01
So in this problem, we're given this matrix m as negative 5, 3, negative 8, 5.
00:08
And what we want to find is m inverse m.
00:16
I want to find out that matrix.
00:19
So i need the inverse of this matrix.
00:22
Okay, so the inverse is 1 over the determinant of m times.
00:30
You swap the down diagonal elements 5 negative 5 and you do the negative on the up diagonal elements negative 3 8 now the determinant of m well we multiply the down diagonal negative 5 times 5 that's negative 25 and we subtract the up diagonal negative 8 times 3 is negative 24 so i have negative 20 25 plus 24, that's negative 1.
01:11
Okay, so that means i have 1 over negative 1 times 5, negative 3, 8, negative 5, which means just basically taking negative 1 times all the elements.
01:23
So negative 5, 3, negative 8, 5.
01:29
Okay, so look what happened.
01:32
The inverse of m is m as it turns out...