When Is A Linear Operator Diagonalizable?
Marco Abate · American Mathematical Monthly · 1997
INTRODUCTION. As it often happens, everything began with a mistake. I was teaching for the third year in a row a linear algebra course to engineering freshmen. One of the highlights of the course was eigenvector theory, and in particular the diagonalization of linear operators on finite-dimensional vector spaces (i.e., of square real or complex matrices). Toward the end of the course I assigned a standard homework: prove that the matrix