Let A = ( ) be an n n matrix. Define a trace of A to be the sum of the diagonal elements, that is
tr(A) = .
(a) Show that the trace is a linear map of the space of n n matrices into K.
(b) If B is invertible, show that tr(B AB) = tr(A).
(c) Prove that there are no matrices A, B such that AB-BA=
Attachment:- problem 11.zip