00:01
So to get to check if these two matrices are inverse, we're just going to do the matrix multiplication and see if our answer comes out to be the inverse or the identity matrix.
00:13
If it does, we know they're inverses.
00:14
If it's not, we know they're not.
00:16
So taking this first column here and multiplying it by the rows here, we're going to get one half times one, one half times one, negative a half times zero.
00:25
So we're going to get a half plus a half gives us one.
00:28
Repeating that process for the second row, we're going to get negative a half, positive, half zero, which will add to zero.
00:35
And then down here we'll get positive a half, zero, negative a half, which again adds to zero...