Let V be the space of n×n matrices over F. Let A be a fixed n×n matrix over F. Let T and U be the linear operators on V defined by
T(B)=ABU(B)=AB−BA.
(a) True or false? If A is diagonalizable (over F), then T is diagonalizable.
(b) True or false? If A is diagonalizable, then U is diagonalizable.