00:01
So in this problem, we're given this matrix a as 1 -0 -0 -negative 1.
00:06
We're first asked to compute a -squared, a -cubed, and a -to -the -fourth.
00:15
Well, a squared would be 1 -0 -0 -0 -1 times itself, 1 -0 -0 -0.
00:24
So row times column.
00:26
So that's 1 times 1 is 1 plus 0, that's a 1, and 0, 0, 0, 0 ,000.
00:35
Well, negative 1 times negative 1 is 1.
00:40
All right, a cubed.
00:41
Well, a cubed is a squared times a.
00:44
So we simply take a squared here, 1001, times a, 1 .00 minus 1.
00:58
Well, this is the identity matrix, isn't it? so this means i'm going to end up with just a again.
01:06
So this is a.
01:08
Okay, a of the 4th.
01:09
Well, that's a squared times a squared, which is i times i, which is i, again, the identity matrix...