For all questions below assume that T V V is a linear operat
     For all questions below, assume that T V V is a linear operator on a finite-dimensional vector space  
  
  Solution
As S has 4 eigenvalues (with possible repetitions) with exaclty 3,4, 7 as the eigenvalues, it follows that exatly one of them is repeated , say 3.
By Cayley Hamilton theorem
(S-3)2 (S-4) (S-7) =0
which implies (S-3)2 (S-4)2 (S-7)2 = (S-4)(S-7) [ (S-3)2 (S-4) (S-7)]
= (S-4)(S-7).o
=0
as required.
Hence proved

