00:01
Okay, so we have this matrix equation where i is the identity, and we also know the determinant of a is not equal to zero, and this is equivalent to saying a is invertible, so a has an inverse.
00:12
We want to rearrange for x.
00:14
So let's do this.
00:15
So firstly, we can subtract the identity from both sides.
00:18
This gives us a squared x equals a, b minus the identity.
00:25
Now we can times both sides on the left by a inverse.
00:28
So we have a inverse.
00:29
I'm going to write a squared as a times a.
00:33
This is a times a times x.
00:37
Again here, now on the right -hand side, we've times by a inverse, so this is a inverse times a b minus a inverse i...