Matrix, Dimensions.
3 by 2 matrix. Because a 3 by 2 matrix times a 2 by 1 matrix or times a 2 by 1 vector, that gives you a 3 by 1 vector. More generally, this is going to be an n1 by n0 dimensional matrix. So what we figured out here is that the dimensions of W1 has to be n1 by n0, and more generally, the dimensions