The n × n matrix A =[aij] is called a diagonal matrix i aij = 0 when i ? j. Show that the product of two n × n diagonal matrices is again a diagonal matrix. Give a simple rule for determining this product.

Solution:Step 1: Let suppose the n × n matrix A =[aij] is called a diagonal matrix i aij = 0 when i j.Step 2We have to show that the product of two n × n diagonal matrices is again a diagonal matrix. Give a simple rule for determining this product.