Let || • || M denote a matrix norm on Rn×n, || ∙ ||v donate a vector norma on Rn ,and I be the n × n identity matrix. Show that
(a) If || • ||M and || • ||v are compatible, then ||I||M ≥ 1.
(b) If || • ||M is subordinate to || ∙ ||v, then ||I||M = 1.