(* Linear Algebra: Theory and Applications *)
(* Ward Cheney & David Kincaid *)
(* JBPub.com (c) 2008 *)
(* File: exp617.mat *)
(* Example 6.1.7      *)

A = {{1,1},{-2,3}}
{DD, P} = Eigensystem[A]
A == P.DiagonalMatrix[DD].Inverse[P]