Apps. and Interpretation for IBDP Maths Ebook 2 | Page 91

www . seprodstore . com 81 7 Let 3 4 5 2 3 4 2 1 0 � � � � � � � � � � � � � � A . ( a ) Write down �1 A . [ 2 ] It is given that 2 3 1 0 1 1 3 3 2 � � � � � � � � � � � � � � AB I , where B and I are 3 3 � matrices . ( b ) Find B . [ 3 ] ( a ) 1 1 5 1 6 24 24 1 5 11 3 12 12 1 11 17 6 24 24 � � � � � � � � � � � � � � � � � � � � � � � A A2 [ 2 ] ( b ) 2 3 1 0 1 1 3 3 2 � � � � � � � � � � � � � � AB I 1 3 1 0 0 1 3 3 1 � � � � � � � � � � � � � AB 1 1 3 1 0 0 1 3 3 1 � � � � � � � � � � � � � � B A ( M1 ) for valid approach Example Solution 26 Paper 1 – Inverse of a Matrix