How to manipulate matrices

Methods: Multiply the elements in the first row of the left matrix by the elements in the first column of the right matrix, and sum them to get the first element in the first row of the multiplication matrix. The element in the first row of the left matrix is multiplied by the element in the second column of the right matrix, and the second element in the first row of the multiplication matrix is obtained by summation, and so on.

It is worth noting that when "matrix multiplication" or "matrix multiplication" is mentioned, it does not mean these special product forms, but the matrix multiplication described in the definition. When describing these special products, use the special names and symbols of these operations to avoid ambiguity.

Matters needing attention in matrix multiplication

1. When the number of columns of matrix A is equal to the number of rows of matrix B, A and B can be multiplied.

2. The number of rows of matrix C is equal to that of matrix A, and the number of columns of matrix C is equal to that of matrix B. ..

3. The elements in row M and column N of product C are equal to the sum of the products of the elements in row M of matrix A and the corresponding elements in column N of matrix B. ..