0:00
Hello.
00:01
So here we have that a is going to be 2 by 3, b is 2 by 3, and c is 3 by 2.
00:06
So if we do a squared minus b c, what is a squared? is a squared has to be defined? first of all, is a square defined? well, yes.
00:14
So if a is going to be a 3 by 3, then a times a is going to give us a 3 by 3 matrix.
00:24
Now what is b c? well, b is going to be 2 by 3.
00:28
So b is 3.
00:30
Two rows, three columns, and c is going to be three by two.
00:36
So c is going to be three by two.
00:41
We multiply these together? yes, this is going to be defined because we have the inner numbers here.
00:46
I'll line up.
00:47
The number of columns of b matches the number of rows of c.
00:51
So what we get there is a two by two matrix.
00:54
So then if we do a squared minus b, c, then we're doing a three by three matrix.
00:59
Subtracting a 2 by 2 matrix, where that is not defined.
01:05
So therefore, which is which other following is true? well, a is not true.
01:10
This is not true...