Suppose 1, dots, is a basis of and TinL() . Prove that if is an eigenvalue of T, then
||² ≤ ∑ⁿⱼ = 1 ∑ⁿₖ = 1 |(T) , |² ,
where (T) , denotes the entry in row , column of the matrix of T with respect to the basis 1, dots, .