The matrices A=(1xy1) and B=(−1xy−1) are inverses. What is xy?
The matrices
A=(1xy1) and B=(−1xy−1)
are inverses.
What is xy?
AB=I(1xy1)(−1xy−1)=(1001)(−1+xyx−x−y+yxy−1)=(1001)(xy−100xy−1)=(1001)
xy−1=1xy=2