1 2 matrix multiplication finding the product of two matricies AB is only possible when the inner dimensions are the same meaning that columns of in the second matrix B first matrix A is equal the the number of to the number of rows if A is an mxr matrix and B is an r x n matrix then the product matrix AB is defined and is an mx n matrix example I given matricies A B C and D determine the following matrix products are defined whether or not if so give the size of the resulting matrix why not 0 A 41 B j y show if not 6 9 1 7 3 5 D 2 12 6 8 3 4 AB 2 2 a AB yes b CB no C CD no d BC yes BC 2 3 e cc yes CCT 2 2 inner dimensions are not the same inner dimensions are not the same