1. The problem statement, all variables and given/known data If A is similar to A^(-1) (=inverse of A), must all the eigenvalues equal 1 or -1? 2. Relevant equations 3. The attempt at a solution I don't know why the textbook gives me the specific value 1 or -1. If A is similar to its inverse, are the eigenvalues really 1 or -1? Why? Help!