www . seprodstore . com 99 7 4 . Let 1 4 0 1 � � � �� � � A . ( a ) ( i ) Find 2 A . ( ii ) Find 3 A . ( iii ) By using the above results , write down 30 A . [ 5 ] Let 0 3 0 1 � � � � �� � � B A . ( b ) ( i ) Show that 2 1 21 0 4 � � � �� � � B . ( ii ) Find 3 B . It is given that 4 B can be expressed as 1 7 14 28 56 0 16 � � � � � � � � � . ( iii ) Find 30 B . [ 8 ] ( c ) Explain why 0 3 det ( ) det ( ) det 0 1 n n n � � � � � � � � � � � � � � � � B A is not always true for 1 n � , n� . [ 1 ]