Question

If A = `[(1,2), (1,3)]`, find A² - 3A

Answer 1

A2 = A . A

= `[(1,2), (1,3)] [(1,2), (1,3)]`

= `[(3,8), (8,11)]`

A² - 3A = `[(3,8), (4,11)] - [(3,6), (3,9)]`

= `[(0,2), (1,2)]`