This is the same as the dot product of the first row vector of matrix A and the first column vector of matrix B. We repeat this process for the entire matrix, resulting in the following calculation for the 2x2
If a 7 \times 9 matrix has rank 5, what are the dimensions of each of its four subspaces? How to scale a matrix? Let W be the vector space of all lower triangular 4 by 4 matrices. What is the dimension of W? How do you find the dimensions of a square matrix?