A and B are 2×2 real valued matrices satisfying
\det A = \det B = 1, \text{tr}(A)>2, \text{tr}(B)>2, \text{tr}(ABA^{-1}B^{-1}) = 2
Prove that A and B have a common eigenvector. matrixlinear algebratracedeterminantcommutatorcommon eigenvectorcollege contests