1.5 若 =digg((a)_(11),(a)_(22),... ,(a)_(mi)), =digg((b)_(11),(b)_(22),... ,(b)_(mi)), 求-|||-(1)A^2;-|||-(2)AB;-|||-(3)当 _(n)neq 0(i=1,2,... ,n) 时,验证-|||-^-1=dig(1)(a)_(11)... ,(|{a)_(min)} );-|||-(4)若 =(({c)_(n))}_(n)times n, 求AC与CA.