Condition Number of a Matrix

Question

Compute the condition number of the following matrix to relative to ||.||_infinity

_{A=[1 -1 -1}

_{0 1 -1}

_{0 0 -1]}

Answer 1

The max row sum matrix norm ||.||_∞ is defined by ||A||_∞ = max_1≤i≤n ∑_1≤j≤n|a_ij|. For example, ||A||_∞ = 5 when A = [ [ -2 3 ] [ 0 4 ] ]. The condition number with respect to a norm ||.|| is defined by cond(A) = ||A|| * ||A^-1||.